Speaker 1: Hey, Daniel, what's the first thing you think about when
Speaker 1: you see something in space you don't understand. Well, my
Speaker 1: first hope is always aliens. But my first thought is
Speaker 1: that it's probably a boring Mistand so as a scientist,
Speaker 1: your mind goes straight to the most dramatic explanation. Yeah,
Speaker 1: we're all hoping that somebody out there hits the science jackpot.
Speaker 1: Everybody wants to find the thing that frocks the world. Yeah,
Speaker 1: you know, people might not realize that science is a
Speaker 1: little bit like playing the lottery. It's mostly wrong numbers,
Speaker 1: but occasionally you get lucky and you win the alien jackpot.
Speaker 1: What's the price you might need to get wiped out? Yeah? Maybe,
Speaker 1: but think about what we might learn along the way
Speaker 1: in our dying moments. I am more hammy cartoonists and
Speaker 1: the creator of PhD comments. Hi, I'm Daniel. I'm a
Speaker 1: particle physicist, and I'm constantly on the hunt for something
Speaker 1: weird in science. Not in your department, in science in general.
Speaker 1: There's plenty of weird things in your department, weird stuff
Speaker 1: growing where it shouldn't be. But no, I'm looking for
Speaker 1: weird stuff in the data, hoping to win that jackpot
Speaker 1: is your data like it's a scratch of kind or
Speaker 1: like you make up the numbers. No, we are just
Speaker 1: looking at particles smashing together and hoping that something that
Speaker 1: comes out of it is unexplained. It's weird, it's something
Speaker 1: that our current theories of physics do not predict. Well,
Speaker 1: congratulations to all of you because you've won the jackpot.
Speaker 1: You are listening to our podcast Daniel and Jorge Explain
Speaker 1: the Universe, a production of I Heart Radio. And your
Speaker 1: prize is that you get to hear all about the incredible,
Speaker 1: amazing mysteries of our universe, all the weird stuff that's
Speaker 1: going on out there, all the little hints we have
Speaker 1: about weird stuff that might be going on that could
Speaker 1: be clues that reveal deep secrets about the nature of reality. Yeah,
Speaker 1: and just like a real lottery, this episode might be
Speaker 1: a winner or a dud. We'll find out. We'll have
Speaker 1: to scratch off the surface. The price is the same
Speaker 1: either way. That's right. The price is right meaning nothing,
Speaker 1: You get what you pay for. But yes, science is
Speaker 1: full of interesting mysteries out there, and it does happen
Speaker 1: a lot, doesn't it. Daniel, did the scientists look out
Speaker 1: into the world, or or try an experiment or do
Speaker 1: something and things don't happen the way you expect them
Speaker 1: to happen. Yep, everybody out there in graduate school knows
Speaker 1: that no experiment goes right the first time. But usually
Speaker 1: the reason you've got a weird result is that you
Speaker 1: messed it up a little bit. You didn't calibrate things,
Speaker 1: or you plug something in backwards, or you misread your
Speaker 1: instrument or something. Usually there's a conventional explanation. But what
Speaker 1: we're all looking for are those moments when you've done
Speaker 1: everything correctly but the answer is not what you expected. Yeah,
Speaker 1: don't they say that the real moments in science or
Speaker 1: not the eureka moments, but them that's interesting moments exactly
Speaker 1: wait a minute moment. There are sometimes those moments. There's
Speaker 1: a fantastic audio tape that's floating out there of recording
Speaker 1: of two astronomers listening to one of the first pulsars
Speaker 1: ever seen. They happen to be recording themselves for reasons
Speaker 1: I don't know, while they were observing, and you can
Speaker 1: hear them going, wait a second, look at this, Oh
Speaker 1: my gosh, is that what we think it is? WHOA
Speaker 1: that's interesting. Really, it's for real. Wasn't acted out so
Speaker 1: those especially they were being recorded. It's for real, it's
Speaker 1: for real. I encourage you to go out there and
Speaker 1: check it out. In fact, maybe we'll dig it out
Speaker 1: for our episode that's coming up on how pulsars were discovered.
Speaker 1: But yeah, most moments of scientific discovery like, dang it,
Speaker 1: my experiment didn't work. Well, maybe there's a better explanation,
Speaker 1: you know, after you check off all the boring explanations.
Speaker 1: Sometimes it's an exciting, fascinating explanation. Something new might be
Speaker 1: going on, or sometimes it's something routine. It could be
Speaker 1: either one absolutely and people might remember few years ago
Speaker 1: we thought we had discovered new trinos going faster than
Speaker 1: the speed of light. I won't say we there because
Speaker 1: I wasn't among the group of people I thought that
Speaker 1: was real. And humanity does something good, it's the royal
Speaker 1: we including when they mess it up, it's them, it's
Speaker 1: the Italians, them Italians. I won't touch that. But as
Speaker 1: soon as that paper came out and I saw that
Speaker 1: it had been written in Microsoft Word, I was like, no,
Speaker 1: there's something wrong with this paper. What do you mean?
Speaker 1: I wrote all my papers in Microsoft word. Yeah, point made.
Speaker 1: Actually I wrote them in Adobie FrameMaker, which tell you
Speaker 1: how old I am A little bit. Wow. That really
Speaker 1: does teach you. But usually, as in the case of
Speaker 1: the Fast and the Lighten New Trinos, is just a mistake.
Speaker 1: In that case, they forgot to plug a cable incorrectly
Speaker 1: and so their calibration was wrong and they mismeasured the speed.
Speaker 1: But sometimes these are famous experiments in the history of physics.
Speaker 1: We see something we don't understand and it's actually a clue.
Speaker 1: It's the first hint of a dramatic realization of uncovering
Speaker 1: something we had no idea about. And a great example
Speaker 1: is the photoelectric effect, which was an experiment around a
Speaker 1: hundred and twenty years ago that was the first clue
Speaker 1: that the universe was quantum mechanical. Yes, it was very
Speaker 1: illuminating and electrifying at the same time for humanity and
Speaker 1: very effective. Yeah. So today we'll be talking about one
Speaker 1: such mystery in science, and in particular in space science
Speaker 1: that happened a few years ago. Daniel right, how long
Speaker 1: ago was this or is it still ongoing? It was
Speaker 1: resolved a few years ago, but it went on for
Speaker 1: several decades. This is an outstanding mystery that puzzled people,
Speaker 1: that caused them to dig deep into their attic of
Speaker 1: ideas for possible boring and exciting explanations for what could
Speaker 1: be happening to this spacecraft. Yes, it involves spacecrafts and
Speaker 1: planets and basically just need toward space and mystery. And
Speaker 1: it's an interesting journey right here. Amazingly, there's almost no
Speaker 1: talk of aliens in this whole topic. Not yet. It
Speaker 1: spressed to surface Daniel and see if we can win
Speaker 1: the library here so to be on the program, we'll
Speaker 1: be talking about what is the Pioneer anomaly. Now, it's anomaly, right,
Speaker 1: not animone, Just get confused. It's not an underwater sea creature.
Speaker 1: It's not something you want deep fried and served before
Speaker 1: your dinner. It's an anomaly. It's something that's not understood,
Speaker 1: that's anomalous, and it's something that happened in space around
Speaker 1: what time. Well, it has to do with the Pioneer spacecraft,
Speaker 1: which was launched in the seventies and has one of
Speaker 1: these incredible careers. You know, they expected to go on
Speaker 1: for several years and then it operated for decades and
Speaker 1: decades and decades and of course it's still out there, right,
Speaker 1: Pioneer ten and Pioneer eleven are still out there flying
Speaker 1: out into the depths of space being pioneers. Of course,
Speaker 1: now I have to admit I did not know what
Speaker 1: the Pioneer spacecraft is or the anomaly. I was a
Speaker 1: little puzzled by this, but as usually, we were wondering
Speaker 1: how many of you out there no or new this
Speaker 1: Pioneer anomaly is. So thank you to everybody who volunteered
Speaker 1: to answer these questions. If you'd like to participate for
Speaker 1: a future episode, please don't be shy. Right to me
Speaker 1: two questions at Daniel and Jorge dot com. So think
Speaker 1: about it for a second. If someone asked you what
Speaker 1: the Pioneer anomaly is or was, what would you say.
Speaker 1: Here's what peopled to say. I don't know, but I
Speaker 1: imagine it's an abnormality're pretending to spacecraft or something. I'm
Speaker 1: not totally sure what the Pioneer a normally is. Um
Speaker 1: I can end the guest that has something to do
Speaker 1: with the Pioneer spacecraft that were launched in the early seventies.
Speaker 1: And I think, and now a very long why, I
Speaker 1: have no idea. I don't know I have no idea
Speaker 1: what the Pioneer anomaly was, but I assume it has
Speaker 1: something to do with the Pioneer spacecraft and obviously something
Speaker 1: that you would not normally expect to have of help them.
Speaker 1: I think that the Pioneer anomally was maybe like this
Speaker 1: first irregularity found about our universe, and since it's the
Speaker 1: Pioneer anomally, I think that this maybe marked like a
Speaker 1: turning point for scientists and made them more curious about
Speaker 1: what other anomalies can be found in our universe. Al Right,
Speaker 1: not a lot of name recognition here, No, I was
Speaker 1: a little surprised. I thought this was a little more famous.
Speaker 1: I remember hearing about this in high school and thinking, woh,
Speaker 1: that's cool. I bet that's something real. Whoa you heard
Speaker 1: about it in high school? Like, oh yeah, like in
Speaker 1: physics class, or how did you hear about it from
Speaker 1: your physics parents. I was a nerd, big shocker, so
Speaker 1: I just kind of interested in this stuff, and you know,
Speaker 1: anything out there in space that was unexplained, anything that
Speaker 1: might be a clue as to how something is working
Speaker 1: in the universe. I gobbled that stuff up to what
Speaker 1: I heard that we didn't understand where this spacecraft was
Speaker 1: and what it was doing, and why I was doing
Speaker 1: these weird things I thought. I think the real anomaly
Speaker 1: is that you used the past tense when you said
Speaker 1: you were a nerd. It's not up to me to
Speaker 1: evaluate that. All right, Well, there is something called the
Speaker 1: Pioneer anomaly, and let's break it down for people. Daniel,
Speaker 1: what is the Pioneer anomaly? So, as expected, it's an
Speaker 1: anomoly that has to do with the Pioneer spacecraft and
Speaker 1: specifically is that we didn't understand where it was going
Speaker 1: and why it seemed to be going off course for
Speaker 1: reasons we did not understand. Okay, so it was a spacecraft,
Speaker 1: meaning like a satellite. I always get confusible to say
Speaker 1: spacecraft because I imagine you know, Battlestar Galactica or you know,
Speaker 1: people in uh in a cockpit or something. But really
Speaker 1: would just mean, like, you know, any device we launched
Speaker 1: into space is called the spacecraft. Yeah, it's not a
Speaker 1: satellite because it's not in orbit around Earth or any
Speaker 1: other sort of body. It's just sort of sent out
Speaker 1: there to explore. And it's called pioneer because it really
Speaker 1: was a pioneering mission. It was the first thing from Earth,
Speaker 1: first scientific object sent out to explore the outer Solar System.
Speaker 1: It was the first man made object to go through
Speaker 1: the asteroid belt. For example, it was the first close
Speaker 1: flyby of Jupiter, Like the first close up pictures of
Speaker 1: Jupiter came from Pioneer. So when was it launched. It
Speaker 1: was a while ago, right, maybe older than us. It's
Speaker 1: been a nerd since longer than I have. Pioneer ten
Speaker 1: was launched in March of seventy two, and Pioneer eleven
Speaker 1: in April of seventy three. And you know, these were
Speaker 1: iconic missions. Before this, we didn't really know what things
Speaker 1: looked like out there. We had telescopes from Earth that
Speaker 1: were pretty good, I guess, nothing compared to what we
Speaker 1: have now. But if you call up in your mind
Speaker 1: an image of Jupiter, you probably have a pretty detailed
Speaker 1: image thanks to Hubble and thanks to all the spacecraft
Speaker 1: we sent to visit close up. But in the seventies,
Speaker 1: if you tried to do that, all you could have
Speaker 1: was like a blurry smear. We just didn't know in
Speaker 1: detail what these planets looked like until we went to
Speaker 1: visit them. So this was the first spacecraft to go
Speaker 1: and do that. Wow, even our telescopes couldn't get us
Speaker 1: a good picture. I mean they were all right, but
Speaker 1: nothing compared to what Pioneer could do. And it was
Speaker 1: an exciting moment even for the public. When these pictures
Speaker 1: started to come back. They had like a prime time
Speaker 1: television show to release these to the public, and people
Speaker 1: were glued to their screens. That TV show actually won
Speaker 1: an Emmy. Really, they had a whole show where they
Speaker 1: just revealed the photographs. Yeah, exactly. It was exciting. People
Speaker 1: wanted to know, so it was really popular. It was
Speaker 1: you know, back in the day, every sort of launch
Speaker 1: was a special moment, and these kind of pictures they
Speaker 1: were priceless. They still are now. Was it a daytime
Speaker 1: Emmy or a prime time Emmy? Those are two very
Speaker 1: different things. I think it was a prime time Emmy.
Speaker 1: That's the good one. Right, Well, it depends on you
Speaker 1: know what you're going for. So they launched a spacecraft
Speaker 1: in seventy two, and they launched like a brother, like
Speaker 1: a sibling sister spacecraft in the next year. Yeah, Pioneer
Speaker 1: ten went to visit Jupiter and then Pioneer eleven did
Speaker 1: Jupiter and Saturn, and this is the end of the series,
Speaker 1: like these are ten and eleven. There was Pioneer six,
Speaker 1: Pioneers seven, Pioneer eight, Pioneer line. Those are in sort
Speaker 1: of solar orbit there like experimental spacecraft to develop the technology.
Speaker 1: But these have all lasted for decades, Like we heard
Speaker 1: from Pioneer ten last in two thousand and three, which
Speaker 1: is like thirty years after we launched it. Wow. Now
Speaker 1: it's kind of weird because if you're like Pioneer number thirteen,
Speaker 1: are you still a pioneering the thirteen first want to
Speaker 1: do something? That's true? But Pioneer tend you know, it
Speaker 1: was the furthest object from humanity for a long time,
Speaker 1: and it was like the farthest humans have had an
Speaker 1: impact on the universe was Pioneer ten. More recently, we
Speaker 1: sent Voyager one, which was launched in seventy seven and
Speaker 1: it was going faster. So it's now the furthest object
Speaker 1: from humanity, even though it left later. Now paint the
Speaker 1: picture for us, what what do these spacecraft look like?
Speaker 1: They basically look like a big satellite dish, which is
Speaker 1: how they communicate back to us, and then there's like,
Speaker 1: you know, a cube of electronics strap to the back
Speaker 1: and that's where you have like instruments and you know,
Speaker 1: things that make measurements. This one has like a cosmic
Speaker 1: rate telescope on it, something to analyze plasma, something to
Speaker 1: analyze radiation. And then they've got a few things sticking
Speaker 1: off of them, like these big arms that stick off,
Speaker 1: and that's where the power sources are. For example, these
Speaker 1: things are powered by radiation. There's a radio isotope thermoelectric
Speaker 1: generator's plutonium in it, and it's basically just plutonium is
Speaker 1: decaying and that the energy from the decay turns into heat,
Speaker 1: which then they turn into electricity, and that powers this thing.
Speaker 1: It's like a plutonium battery. Well, it's a nuclear powered
Speaker 1: spacecraft basically, right, Yeah, how else could you power this thing?
Speaker 1: Solar panels wouldn't be effective after decades when you're so
Speaker 1: far from the Sun that it just looks like another star,
Speaker 1: and we couldn't charge up our batteries and send them
Speaker 1: out there. So really nuclear power is the only way
Speaker 1: to power these very very long lived spacecraft. All right.
Speaker 1: So we sent it out, and we sent it out
Speaker 1: to Jupiter and Saturn, and as something happened along the way,
Speaker 1: something weird happened. Yeah, the weird thing is that it
Speaker 1: wasn't flying the way that we thought it should. A
Speaker 1: Pioneer turns out to be sort of unexpectedly a really
Speaker 1: really sensitive instrument to measure gravitational pull of everything in
Speaker 1: the Solar System, and that's because it almost never fires
Speaker 1: its thrusters. It's just sort of like a ball we
Speaker 1: threw out into space. A lot of the other satellites
Speaker 1: that we send out there, like Voyager, it's got a
Speaker 1: bunch of thrusters and it's constantly firing them to change
Speaker 1: this direction. So it's hard to predict exactly where it
Speaker 1: should be. A Pioneer, it's just spin stabilized, and we
Speaker 1: just launched it out there, so we can use sort
Speaker 1: of Newton's theory of gravity and then Einstein's modification to
Speaker 1: predict exactly where it should be at any given moment.
Speaker 1: And when they measure to see where it actually was,
Speaker 1: it turns out it was kind of off course. Wait
Speaker 1: a minute. First of all, we just threw it out there.
Speaker 1: It doesn't have like, you know, a thrusters to steer
Speaker 1: it or to change its direction. It does have some
Speaker 1: small thrusters and a little bit of fuel but these
Speaker 1: are just in case it needs, of course correction. But yeah,
Speaker 1: unlike later, spacecraft is primarily just like a rock that
Speaker 1: we throw out into space. Now we keep it spinning
Speaker 1: a right that helps stabilize it to go in the
Speaker 1: right direction. But essentially we just toss it out there
Speaker 1: and then we just measure to see where it went,
Speaker 1: and that tells us something about like the gravity that
Speaker 1: experiences along the way. That's wow. And how do we
Speaker 1: know where it is? If we just throw it out
Speaker 1: on into space. It sends us messages and it answers messages,
Speaker 1: and we can tell how far away it is by
Speaker 1: how long those messages take to come back. And we
Speaker 1: can also tell how fast it's going by the Doppler
Speaker 1: shift of its messages. The faster it's going, the more
Speaker 1: the wavelength is change of the messages that return. So
Speaker 1: we have those two pieces of information, how far away
Speaker 1: it is and how fast it's going. And I guess
Speaker 1: we triangulate like if we've talked it one day and
Speaker 1: then we talked it the next month, and we can
Speaker 1: sort of as the Earth move, we can is that
Speaker 1: how we can tell where it is? Yeah, Also because
Speaker 1: we can tell where the signal is coming from right
Speaker 1: and located in the sky, and so we can tell
Speaker 1: where it is, how far way it is, and how
Speaker 1: fast it's moving, and then we compare that to like
Speaker 1: our model of where we think it should be. Are
Speaker 1: you want to keep up to date and like is
Speaker 1: this thing going in the right direction and isn't it
Speaker 1: a crash into Jupiter or just fly by? Right? All right?
Speaker 1: So then we threw this spacecraft into space and it
Speaker 1: didn't go where we thought it would, right, that's the anomaly.
Speaker 1: That's the anomaly. It was hundreds of kilometers off course.
Speaker 1: Something was pulling on this thing. It was slowing it
Speaker 1: down in a way that we did not understand. There's
Speaker 1: some small acceleration of this thing towards the Sun that
Speaker 1: didn't have an explanation from any known physics. Weird, hundreds
Speaker 1: of kilometers off course, that's that's not a little. It's
Speaker 1: not a little like if I if I missed an
Speaker 1: address by kilometers of being another state. Yeah, it's actually
Speaker 1: a really really tiny effect, but it adds up over
Speaker 1: the thousands and thousands kilometers of its journey. The effect
Speaker 1: of this force, this unexplained anomalous force, is ten billion
Speaker 1: times smaller then the acceleration we feel here on Earth
Speaker 1: from the gravitational pull of the Earth. So that's small
Speaker 1: effect really adds up over the lifetime the decades of
Speaker 1: this craft's flight to get it hundreds of kilometers off course,
Speaker 1: all right, And so and we knew one thing about it,
Speaker 1: which is that this mystery acceleration was directed towards the Sun.
Speaker 1: That's one clue. That's one clue. The other clue was
Speaker 1: that the same thing happened for Pioneer eleven wasn't just
Speaker 1: like some weird thing like, oh, maybe we shot Pioneer
Speaker 1: tan off in the wrong direction or make a mismeasurement
Speaker 1: early on, like the same thing happened to another spacecraft.
Speaker 1: I see, did it happen for Pioneer one through nine? Uh?
Speaker 1: Those guys didn't go out into the outer Solar System,
Speaker 1: so they didn't get a chance to probe that. I see.
Speaker 1: They weren't true pioneers. Yeah, And the Voyager missions which
Speaker 1: went out sort of in the same area, they had
Speaker 1: lots of complicated thrusters and were always doing these adjustments,
Speaker 1: and so they weren't nearly as precise probes of gravity.
Speaker 1: They weren't just like pure flying rocks. All right, so
Speaker 1: that's the Pioneer anomaly, the big mr. What was happening
Speaker 1: to the spacecraft that was steering them off course. So
Speaker 1: let's get into what could be possible explanations for this
Speaker 1: effect and also how it was possibly fixed. But first
Speaker 1: let's take a quick break. All right, we're talking about
Speaker 1: the Pioneer anomaly. These are spacecraft we launched in the
Speaker 1: seventies out towards Tupiter and Saturn, and they sort of
Speaker 1: got off course for some mysterious reason. Daniel, Um. These
Speaker 1: are spacecrafts that are still out there, right. They're gonna
Speaker 1: be out there for a long time. They're gonna be
Speaker 1: out there forever. They just keep going, right. There's nothing
Speaker 1: we can do to stop them or pull them back.
Speaker 1: They're just sort of headed out into the galaxy. They
Speaker 1: won't run out of batteries. They will run out of
Speaker 1: batteries eventually, you know, the half life of their plutonium
Speaker 1: batteries like eighty seven years, So it's gonna go for
Speaker 1: a while. But yeah, eventually it will run out of battery.
Speaker 1: But that's not going to stop it, right, It doesn't
Speaker 1: need battery to go. It just has its velocity and
Speaker 1: it just keeps flying. Oh wow, like basically too trash
Speaker 1: out into space. He'll be there forever. But we labeled
Speaker 1: our trash, right, we put our names on it. We
Speaker 1: said exactly who we are and what we're like found,
Speaker 1: come conquer us and us. This is reperiment on us. Yeah,
Speaker 1: it's commediently pointing towards us, right, yeah, exactly. And we
Speaker 1: put a plaque on it. We said exactly how to
Speaker 1: get to Earth. We put like a pulsar map, so
Speaker 1: if you knew where the pulsars were in the galaxy,
Speaker 1: you could exactly triangulate where our solar system was. We
Speaker 1: put a picture of humans on it. We even recorded
Speaker 1: some sounds from Earth and put it on there, as
Speaker 1: if like they would know how to play a record
Speaker 1: and know how to interpret that. So we threw these
Speaker 1: spacecraft out into the outer Solar system and they started
Speaker 1: veering off course for some mysterious reason. Now that people
Speaker 1: freak out or were they just sort of puzzled about
Speaker 1: this At first, they were just puzzled and they figured, well,
Speaker 1: we must have made a mistake somewhere, or there's tiny
Speaker 1: little effect that we hadn't accounted for, because you know,
Speaker 1: it's not just as simple as you toss a rock
Speaker 1: out into space and then you do gravitational calculations. There
Speaker 1: are lots of really small effects. You know. One set
Speaker 1: of small effects is like, well, there's a lot of
Speaker 1: different sources of gravity. It's not just the Sun that's
Speaker 1: pulling on these things, and it's all the planets and
Speaker 1: all the moons and all the rocks in the asteroid
Speaker 1: belt and all the tiny little things in the Kuiper Belt,
Speaker 1: and you know, even other stars provide tugs. So at
Speaker 1: first people thought, oh, we just haven't been as careful
Speaker 1: as we needed to to sort of tie up all
Speaker 1: the loose ends I see, like there could have been
Speaker 1: like it may be passed by a big asteroid that
Speaker 1: maybe pulled it off course or something. Yeah, or even
Speaker 1: simple things like maybe we're analyzing the data wrong, you know,
Speaker 1: we mismeasured it or misinterpreted this result or something like that. First,
Speaker 1: when you see something weird in your data, that's your
Speaker 1: assumption is that we messed up or we just weren't
Speaker 1: thorough enough. And the cool thing about pioneers that's very
Speaker 1: very precise data, and so it allows for really detailed tests,
Speaker 1: and so you can like go through your whole list
Speaker 1: of ideas for what could be affecting the flight of
Speaker 1: this thing, add them all up, and then compare them
Speaker 1: to the number. It's a really valuable way to check
Speaker 1: your understanding, right because I imagine you know, like you said,
Speaker 1: your first wish is that it's aliens. But I imagine
Speaker 1: you're also sort of afraid a little bit, like, oh
Speaker 1: my god, what if I made a mistake, Like what
Speaker 1: if I I am totally doing this where I have
Speaker 1: a typo in my formula or something. Right now, does
Speaker 1: that emotion also pass through you? I'm sure it does,
Speaker 1: you know. For those guys, you remember there was one
Speaker 1: Martian probe that crashed because somebody typed the number in
Speaker 1: in the wrong units, Like there was a European group,
Speaker 1: an American group, and somebody put something in in pounds
Speaker 1: and somebody else interpreted in kilograms and oops, and then
Speaker 1: the whole thing crashed and burned. So yeah, mistakes do happen, absolutely, Yeah,
Speaker 1: just don't work with those Americans and they're non international system.
Speaker 1: In my personal research, there's very little opportunity for aliens
Speaker 1: to affect our data. I mean, that would be pretty
Speaker 1: awesome if aliens change the collisions at the LHC and
Speaker 1: cause new weird stuff to happen as a way to communicate. Actually,
Speaker 1: that would be a pretty cool science fiction story, right,
Speaker 1: discovering aliens through particle collisions. Alien pranksters, alien physics pranksters.
Speaker 1: Exactly exactly, Aliens, if you're listening, I welcome that. Please
Speaker 1: mess with our data. It's the large age on coliders.
Speaker 1: Send us a message. The first physics from camm Alright, so,
Speaker 1: so what were some of the things that they thought
Speaker 1: could be happening here with the Pioneer anomaly. Well, the
Speaker 1: first thing that comes to mind is just the location
Speaker 1: of everything in the Solar System. So they went back,
Speaker 1: they did a really detailed check and they thought, for example, like,
Speaker 1: how well do we actually know the location of all
Speaker 1: the planets, you know, Earth and Jupiter and Saturn. If
Speaker 1: those are off by a little bit, could that explain
Speaker 1: you know, a little gravitational tug. And you know, we
Speaker 1: know these things really well because we've been watching these
Speaker 1: planets for a long time and they mostly just obayue gravity.
Speaker 1: So we have really really detailed models. We know the
Speaker 1: location these planets down to the meter, and these effects
Speaker 1: are just too small. So, like we think we know
Speaker 1: the gravity from all the planets and all the little
Speaker 1: things in the Solar system, there is uncertainly there, but
Speaker 1: it can't explain an effect of this size, all right,
Speaker 1: So it wasn't our measurement of the planets could be
Speaker 1: the measurement of you know, asteroids, because there is a
Speaker 1: lot of dark asteroids out there. There were some asteroids
Speaker 1: out there, but those are all really small. You know. Remember,
Speaker 1: gravity is really weak, and so to have any sort
Speaker 1: of effect, you either have to be large or you
Speaker 1: have to be close. So because the same thing happened
Speaker 1: to Pioneer eleven, we didn't think it was like a
Speaker 1: one off event that just like some object happened to
Speaker 1: get near one of these things. So it seemed like
Speaker 1: it had to be some sort of more systemic thing.
Speaker 1: Another thing people thought about is like, well, what about
Speaker 1: the solar wind? Right, the Sun is pushing on things,
Speaker 1: It's not just tugging on them with gravity is actually
Speaker 1: pushing on everything. You know, it's sending out streams of particles.
Speaker 1: You could use that as a solar sales and navigate
Speaker 1: the Solar system. So if you're like hunting down for
Speaker 1: tiny little effects. You might want to consider the effects
Speaker 1: of the photons and the protons and the electrons that
Speaker 1: the Sun is streaming out right, but the solar wind
Speaker 1: is pushing things up. But here something was kind of
Speaker 1: pulling the spacecraft towards the Sun right exactly, So it's
Speaker 1: the wrong direction. If anything, you would expect the solar
Speaker 1: wind to accelerate it, to push it further out into
Speaker 1: the Solar system, making go faster. So we needed some
Speaker 1: other effects, something that was tugging it back into the
Speaker 1: Solar system. And so this long list of basic checks
Speaker 1: were done, and none of them could explain what was
Speaker 1: going on. None of them are sort of strong enough
Speaker 1: to account for the deviations of hundreds of kilometers, So
Speaker 1: it wasn't the basic stuff. Then that's when people started
Speaker 1: to get creative. I imagine, Yeah, they started to get creative.
Speaker 1: They thought, well, what if there's something else on the
Speaker 1: spacecraft that's basically giving it a little push. You know
Speaker 1: what if there's like effectively a thruster, Because think about
Speaker 1: the batteries on these spacecraft. These things generate heat, and
Speaker 1: things that are hot radiate photons, and when you radiate
Speaker 1: a photon, you're basically getting pushed. You know, you shoot
Speaker 1: off a photon to the left, then by conservation momentum,
Speaker 1: you're going to the right, and everybody, everything that is
Speaker 1: hot is giving off photons. Like me and you, we
Speaker 1: glow in the infrared. Right, you put on night vision
Speaker 1: goggles like the Predator, you can see a human body
Speaker 1: because it's giving off in for a red photon. I
Speaker 1: knew you would work in aliens somehow. Wait does that mean?
Speaker 1: Like if I put a flashlight out into space and
Speaker 1: turn it on, it would start to go like it
Speaker 1: would basically act like a rocket. Yes, a flashlight is
Speaker 1: a rocket, absolutely. It throws particles out the back, and
Speaker 1: so it has to go the other direction. Now, if
Speaker 1: you put two flashlights shining in the opposite directions, it
Speaker 1: won't go anywhere. They'll balance each other. So the pioneer
Speaker 1: people thought, well, it's got these things on it, but
Speaker 1: they glow in every direction, right, and so if heat
Speaker 1: is the same everywhere in the spacecraft, that's not going
Speaker 1: to effectively give it a push. When did? It depends
Speaker 1: on the shape, Like a hot sphere would give up
Speaker 1: photons in all directions, But maybe, like I don't know,
Speaker 1: like it's something it looks like a dish might not. No,
Speaker 1: you're right, and it's a really interesting clue. And people
Speaker 1: thought for a while about this, like maybe the complicated
Speaker 1: shape of the spacecraft is not giving off heat in
Speaker 1: the same direction everywhere. But there was another important clue,
Speaker 1: which was that this effect wasn't dropping as a function
Speaker 1: of time, like it wasn't fading. And we know the
Speaker 1: heat from these batteries should be fading, like this is
Speaker 1: a radioactive thing. It decays over the half life of
Speaker 1: eighty seven years. These things eventually cool and then just
Speaker 1: become dead. And so if it's due to the heat
Speaker 1: of the batteries, you would expect this thing to fade
Speaker 1: with time. But the data we had showed that it
Speaker 1: was constant. So people thought, well, can't be the batteries.
Speaker 1: I see, it wasn't cool enough. It wasn't getting cool alright,
Speaker 1: So then what else did did they think it could be?
Speaker 1: So that's when he got exciting. They thought, well, we
Speaker 1: can't explain this using any sort of known physics, any
Speaker 1: solar wind or any gravity or any heating of the spacecraft,
Speaker 1: so let's get creative. And people thought, well, maybe we've
Speaker 1: accidentally created something which measures like the expansion of the universe,
Speaker 1: because they thought maybe space is expanding inside the Solar
Speaker 1: System and it creates this weird gravitational potential. And we
Speaker 1: know that gravity and time are connected because, for example,
Speaker 1: if you go near a black hole, time slows down
Speaker 1: for you. So over vast stretches of space, potentially time
Speaker 1: is getting slowed down as you move through these like
Speaker 1: expanded space. Whereas our clocks, the ones that we're using
Speaker 1: to sort of predict where this thing goes, these really
Speaker 1: precise atomic clocks basically assume that space is flat. So
Speaker 1: if we're measuring time differently than something that's flying out
Speaker 1: into the Solar System, then maybe that could explain it,
Speaker 1: meaning like maybe the clock on the spacecraft is wrong
Speaker 1: or do you mean like it's actually in a different time,
Speaker 1: it's actually in a different time. Yeah, this falls under
Speaker 1: this whole set of ideas like the non uniformity of time, right,
Speaker 1: And we've talked a lot in the podcast about how
Speaker 1: my clock and your clock can disagree but both be
Speaker 1: correct because there is no universal sense of time. So
Speaker 1: this is an idea sort of along that direction, like
Speaker 1: maybe we're measuring the expansion of space and those gravitational
Speaker 1: effects are distorting the clock on the spacecraft, not that
Speaker 1: it's wrong, but you know it's different. It's just differently timed.
Speaker 1: I see. So maybe the idea is that maybe it
Speaker 1: is it was supposed to be, but our measurement of
Speaker 1: where it is is wrong because the timing in the
Speaker 1: clock on board is different than it we think it
Speaker 1: should be. And that was so the general concept like
Speaker 1: maybe something in this direction will help us because we
Speaker 1: know gravity and time are connected. But they couldn't actually
Speaker 1: make it work. They try to get the map all
Speaker 1: work out and say, is this consistent with general relativity?
Speaker 1: What we know about the expansion in the universe? Would
Speaker 1: that explain that? And it could never be made consistent,
Speaker 1: and so it would have to be like some weird
Speaker 1: deviation have to be some special case of how times
Speaker 1: affected by gravity for some reason only in our solar system.
Speaker 1: And so you know, when you start to develop like
Speaker 1: a new idea of for how to explain some weird science,
Speaker 1: you want as simple a new idea as possible. You
Speaker 1: don't want to have to like add all sorts of
Speaker 1: weird bells and whistles and exceptions and stuff. And so
Speaker 1: this started off sort of promising and then ended up
Speaker 1: being like, it doesn't really fit. It wasn't just that
Speaker 1: they it was in the wrong time zone or daylight savings.
Speaker 1: That couldn't explain it either. No, I mean I make
Speaker 1: that mistake all the time, and they usually blame it
Speaker 1: on aliens, which is why I miss a meeting. But no,
Speaker 1: they couldn't explain this using any sort of general relativistic
Speaker 1: effects on the clock or even simple modifications to general
Speaker 1: relativity to allow for effects on the clock of the
Speaker 1: expanding space in the Solar System. So that didn't work out.
Speaker 1: You can't blame the engineers, and you can't blame Einstein
Speaker 1: or general relativity. What else could it have been. Well,
Speaker 1: people got excited for a while when they thought maybe
Speaker 1: it was dark matter. Right, we've accounted for the gravitational
Speaker 1: sources that we know about the planets and the rocks
Speaker 1: and the Sun, But we also know that most of
Speaker 1: the gravity in the Unit verse isn't from the stuff
Speaker 1: that we can see. It's actually from this weird invisible matter.
Speaker 1: We still won't understand that's everywhere, and we think that
Speaker 1: it fills the galaxy. In fact extends beyond the galaxy
Speaker 1: and it's five times as much of it as there
Speaker 1: is normal matters. So if you're studying details of gravitational effects,
Speaker 1: you might expect to have to take into account the
Speaker 1: dark matter. Interesting. Yeah, like our solar system could be
Speaker 1: or is probably bated in dark matter, right, that could
Speaker 1: potentially affect the gravity of things we send out into space. Absolutely,
Speaker 1: dark matter definitely is here. It's everywhere. It's all around us.
Speaker 1: There's dark matter with us in this room, the dark
Speaker 1: matter all around the Earth. We can't see it or
Speaker 1: detective because we think it only has a gravitational interaction.
Speaker 1: And remember gravity is super duper weak, so usually we're
Speaker 1: only sensitive to dark matter if there are huge amounts
Speaker 1: of it, you know, like galaxy sized amounts to affect
Speaker 1: how the galaxy spins. It's really hard to detect like
Speaker 1: local blobs of dark matter. So people got excited when
Speaker 1: they thought maybe Pioneer ten and eleven are like a
Speaker 1: local prob they're telling us how much dark matter there
Speaker 1: is here. Interesting, But wouldn't if there was some anomaly
Speaker 1: in dark matter, wouldn't it affect all the other planets too? Yeah, exactly,
Speaker 1: it would. And we also don't think that there is
Speaker 1: that much dark matter. We know that there's five times
Speaker 1: as much dark matter in general in the universe, but
Speaker 1: we don't think in our Solar System there's that much
Speaker 1: because doesn't clump up we think the way normal matter does.
Speaker 1: Like if you took the normal matter in the galaxy
Speaker 1: and just spread it out throughout the whole volume of
Speaker 1: the galaxy, it would be pretty thin. That's the way
Speaker 1: dark matter is. There's five times as much of it,
Speaker 1: but it's much more spread out than normal matter is.
Speaker 1: So sort of in the volume of the Solar System,
Speaker 1: it's like one million of the mass of the Sun
Speaker 1: of dark matter, right, see, So it couldn't be that either.
Speaker 1: So then they couldn't blame it on a technical issue
Speaker 1: or sort of a theoretical issue, And so it was
Speaker 1: a big mystery, I mean for decades, right, Like they've
Speaker 1: seen this anomaly for you know, a thirty almost forty years. Yeah,
Speaker 1: people really worked on it for a long time, and
Speaker 1: it was in the nineties of people that is really
Speaker 1: detailed investigation went through all these possible explanations and couldn't
Speaker 1: explain it, And then people had a lot of fun
Speaker 1: coming up with theories of new physics to try to
Speaker 1: explain it potentially, and it's sort of like a standing
Speaker 1: question in science for quite a while. People even try
Speaker 1: to explain it using like weird modified gravity, like maybe
Speaker 1: gravity doesn't work the way Einstein and Newton thought we did,
Speaker 1: and somehow gravity changes when you get out into the
Speaker 1: outer Solar system. But you know, that doesn't really make
Speaker 1: sense because we understand how Pluto and Neptune and Neurinus operate.
Speaker 1: So there are a lot of questions about what could
Speaker 1: explain this on a lot of crazy ideas thought up
Speaker 1: to explain it, none of which were ever really very
Speaker 1: compelling or which worked. So it's sort of a question like,
Speaker 1: are we gonna find some boring explanation for what this is?
Speaker 1: Or is somebody going to come up with a new
Speaker 1: idea that actually, you know, makes it all click together
Speaker 1: and tells us something new and deep about the universe? Right?
Speaker 1: Are you going to get a try again when you
Speaker 1: scratch out the start of it? Or are you gonna
Speaker 1: win a million aliens in the process. All right, Well,
Speaker 1: let's get into how this mystery was finally resolved, if
Speaker 1: it was resolved at all. But first let's take a
Speaker 1: quick break. All right, So the Pioneer anomaly was a
Speaker 1: big mystery for decades back in the seventies, eighties, and nineties,
Speaker 1: spacecraft we throughout their into space. We're veering off course, Daniel,
Speaker 1: How was it all resolved in the end. If it
Speaker 1: was so, we actually do think we have a pretty
Speaker 1: good understanding of what happened by now, and it's due
Speaker 1: to some sort of like data archaeology by some researchers
Speaker 1: really dedicated, really interested in understanding how this worked. They
Speaker 1: went and found some old data in the mid two
Speaker 1: thousand's and did a really detailed study and they think
Speaker 1: they've cracked it. Oh wow, in the mid to of thousands.
Speaker 1: So all this time, since the seventies, these space crafts
Speaker 1: were out there off course and people just sort of
Speaker 1: shrugged it off for a while, or that they just
Speaker 1: gave up, or or what. Well, you know, when there
Speaker 1: are these puzzles in science, it's not always easy to
Speaker 1: know how to crack them, and so sometimes they'll be
Speaker 1: out there for a long time, decades even people like,
Speaker 1: well that's not understood, but nobody really knows what to
Speaker 1: do about it. So finally somebody said, well, I'm gonna
Speaker 1: try to go back and find some more data, dig
Speaker 1: out some mold data nobody's ever seen before, and make
Speaker 1: a more detailed study than anybody's ever done before, and
Speaker 1: maybe we'll figure it out. Wow, that's wild to me, Like,
Speaker 1: how do you sleep at night? Like, let's say you're
Speaker 1: the scientists or the engineer who worked on this, Like,
Speaker 1: how do you ever be at peace? You know, It's
Speaker 1: like if somebody told you, hey, I know it's your
Speaker 1: car mysteriously moves an inch every night, and you're like, well,
Speaker 1: I don't know, how could you get to sleep? I
Speaker 1: think that's why smart scientists have great ideas in the
Speaker 1: middle of the night, because their brains are always working
Speaker 1: on these things, are always chewing away on these puzzles
Speaker 1: and these questions. All right. So then in the two thousands, UM,
Speaker 1: a group of people said, hey, we want to figure
Speaker 1: this out. So they say, sort of dug through all
Speaker 1: the old data. But that was kind of hard, right,
Speaker 1: because this is data from the seventies. Yeah, they literally
Speaker 1: dug through old data and they were specifically focused on
Speaker 1: this question of the heat from the batteries and whether
Speaker 1: or not it really was decaying over time. And what
Speaker 1: they discovered is that we didn't actually have all the data.
Speaker 1: Some of the earliest data from the spacecraft was like
Speaker 1: stored on magnetic tapes and not really included in most
Speaker 1: later analyzes because it was kind of a pain to
Speaker 1: go and find it and recover it and process it
Speaker 1: and stuff. So they did a bit of like archaeology,
Speaker 1: and they found more than a dozen boxes of magnetic
Speaker 1: tapes stored under a staircase at JPL in Pasadena, and
Speaker 1: they worked with like an old school programmer to create
Speaker 1: software that could read these tapes and clean it up.
Speaker 1: So they got sort of a longer time series on
Speaker 1: the data than anybody else had, like data on what
Speaker 1: the position of it, or like the signals we were
Speaker 1: getting from it, or what on the position of it is,
Speaker 1: specifically the earlier positions. Remember we talked about how we
Speaker 1: didn't think it was just heat coming off the spacecraft
Speaker 1: unevenly because it would have faded with time, and it
Speaker 1: didn't look like it was fading with time. So to
Speaker 1: trying to answer that question in more detail, they said, well,
Speaker 1: let's look at earlier data data when it had just
Speaker 1: left the Earth to see if we can spot this
Speaker 1: effect earlier on. I see, you're looking for a weird
Speaker 1: effect on where you think it should be different from
Speaker 1: when then we're where it is, right, yeah, exactly. So
Speaker 1: you're you're basically comparing curves. Right, you have the curve
Speaker 1: of what you expect and the curve of where it
Speaker 1: actually was. And now you're trying to come up with
Speaker 1: a new expectation, like can we tweak how we understand
Speaker 1: this thing flies so that what we expect matches what
Speaker 1: we observe. And you also have to sort of look
Speaker 1: back in time in the Solar system, right, like in
Speaker 1: this back then, what where were all the planets and
Speaker 1: asteroids and all that in order to think about where
Speaker 1: it should have been exactly. It's a complicated calculation, and
Speaker 1: to do this right you need to know not just
Speaker 1: where it was, but you also need to know, as
Speaker 1: you were saying, where it's giving off heat. Like the
Speaker 1: shape of this thing really affects how it glows, because,
Speaker 1: as we're talking about before, it's not just a sphere, right.
Speaker 1: Physicists always like to assume everything is a spear at
Speaker 1: first order, but the details matter when you're making really
Speaker 1: really precise measurements. And this thing has two big hot
Speaker 1: batteries on one side, and then like a cool dish
Speaker 1: on the other side. But it also has a bunch
Speaker 1: of instruments that use that electricity, and so as they
Speaker 1: draw current, they get hot, and as the heat up,
Speaker 1: they glow, and these kind of effects. Is just the
Speaker 1: glowing heat from these things is big enough to explain
Speaker 1: the effect that we're seeing. Yeah, and I think you know,
Speaker 1: you say batteries and that makes me think of, you know,
Speaker 1: like as a battery or a car battery. But really
Speaker 1: these are like nuclear reactors right there their generators, Yeah, exactly,
Speaker 1: they're not fission or fusion. They're just sort of like
Speaker 1: slow rolling radioactive to k that generates the electricity. But yeah,
Speaker 1: they are nuclear reactors. But also everything on the space
Speaker 1: scrapt that he uses that electricity eventually leaks some of
Speaker 1: that energy. Nothing is perfect, right, and it leaks that
Speaker 1: energy into heat, just the same way everything that you
Speaker 1: use as electronics in it will eventually heat up. Your
Speaker 1: computer heats up as you use it. Right, there's no
Speaker 1: like fire burning inside your computer. It's just inefficiency from
Speaker 1: the use of electricity. So if you have an object
Speaker 1: on a spacecraft that's drawing electricity, not even just the batteries,
Speaker 1: but the equipment on the spacecraft gets hot as it
Speaker 1: uses the electricity. To understand the effect of all this stuff,
Speaker 1: you need to know like exactly where everything was on
Speaker 1: the spacecraft and how hot it got. These days, we
Speaker 1: can do that pretty well. We have like really fancy
Speaker 1: software to model this kind of stuff, but you know,
Speaker 1: we don't have the records that match that software from
Speaker 1: a really really old instrument, Like this thing was built
Speaker 1: forty years ago. You know, we have like blue plants
Speaker 1: drawn by hand by the original designers. So these researchers
Speaker 1: had to go in and build a model of the
Speaker 1: sort of heat flow of Pioneer spacecraft by hand like later.
Speaker 1: And it's involved like fifteen thousand individual pieces like exactly
Speaker 1: where this cable goes and exactly how thick that piece
Speaker 1: of aluminum it was, and like this is a huge effort. Wow.
Speaker 1: So yeah, they had to basically create a virtual model
Speaker 1: of the spacecraft and then put it out into space
Speaker 1: with the heat source and see if it would deviate
Speaker 1: the way that we they were seeing in the data.
Speaker 1: It's really incredible precision. You know. Think about like when
Speaker 1: you drive your car, do you expect your car to
Speaker 1: slow down when you turn the headlights on right. You
Speaker 1: don't expect it to, but actually it does. Right. Turning
Speaker 1: on the headlights slows down your car because you're basically
Speaker 1: shooting photons away from your car. So this is the
Speaker 1: kind of effect that we're looking for. It's amazing that
Speaker 1: it actually happens and they were able to figure it out.
Speaker 1: So now they're calculations, which include more time information and
Speaker 1: a much more detailed model of the spacecraft actually match
Speaker 1: really well what we see. So they think they solved
Speaker 1: the mystery. They think they've solved the mystery. Turns out
Speaker 1: it was the plutonium in the power source next to
Speaker 1: Saturn exactly. It's just uneven heating right eventually over many years.
Speaker 1: The fact that one side of this thing is hotter
Speaker 1: than the other means that it gave off more photons,
Speaker 1: which gave it a little bit of a push. It's
Speaker 1: like if you had two flashlights out in space and
Speaker 1: one of them was a teensy bit brighter than the
Speaker 1: other one, you would get pushed away from that flashlight,
Speaker 1: tiny little bit. And that explains why it was being
Speaker 1: pulled towards the Sun. Because you know that the way
Speaker 1: this basecraft is designed, you know you always want to
Speaker 1: point the dish back towards Earth kind of right, And
Speaker 1: so that means that the hot stuff is sort of
Speaker 1: in front of you, which was slowing it down. M Yeah,
Speaker 1: we're pointing the hot bits of this thing out towards
Speaker 1: the Aliens and the cold side back towards Earth. So yeah,
Speaker 1: that effectively slows it down a tiny little bit. I
Speaker 1: guess the lesson is, you know, it's always better to
Speaker 1: have a hot back end. I'm not going to touch
Speaker 1: that at all, but Pioneer eleven apparently had the same
Speaker 1: hot back end, and that's why the same thing happened
Speaker 1: to Pioneer eleven. The story all sort of fits together
Speaker 1: and makes sense. And I love these sort of science
Speaker 1: stories when it all this clicks together and the explanation
Speaker 1: matches the data and it all just sort of works.
Speaker 1: It's like, man, math is correct, physics works, the universe
Speaker 1: actually makes sense. It's incredible. I guess you're simultaneously impressed
Speaker 1: by yourselves but also disappointed that you're so good at
Speaker 1: figuring out the universe. Kind of yeah, it's not as
Speaker 1: exciting an explanation is like we discovered a new way
Speaker 1: that time flows, or gravity is broken, or something like that,
Speaker 1: or we have a clump of hidden dark matter in
Speaker 1: the Solar System that would be more exciting, but you
Speaker 1: never know, Like science is about exploration, which means you
Speaker 1: never know what you're gonna find. Usually it's boring dust
Speaker 1: and rubble, but sometimes sometimes it's a real diamond, it's
Speaker 1: a gem, something that gives you a clue about the
Speaker 1: nature of reality, and you never know, which is why
Speaker 1: you just gotta keep scratching, all right. So then this
Speaker 1: is sort of in the community, this is the most
Speaker 1: accepted explain aation of what happened. Like everyone feels like,
Speaker 1: all right, these researchers totally nailed it, they totally explains it,
Speaker 1: or is there still some sort of uncertainty about it both.
Speaker 1: I think people accept this as an explanation for what
Speaker 1: happened to Pioneer ten and Pioneer eleven, So that sort
Speaker 1: of anomaly has been solved, but there are still plenty
Speaker 1: of anomalies and how spacecraft moved, not just Pioneer ten
Speaker 1: and Pioneer eleven, but every spacecraft that does one of
Speaker 1: these sort of gravitational slingshots ends up going off in
Speaker 1: the direction that we don't quite understand. This is called
Speaker 1: the fly by anomally. Basically, every time one of these
Speaker 1: things happens, it doesn't quite work out the way we
Speaker 1: expect and nobody really understands it. So there's a long
Speaker 1: list of things we don't understand about how things move
Speaker 1: into Solar system. Even though as basic as just like
Speaker 1: gravitational mechanics about things moving in the Solar System, still
Speaker 1: have questions that need to be answered, right, which is
Speaker 1: all the more impressive that they can. I'm gonna say
Speaker 1: we because this is a good thing, So I'm gonna
Speaker 1: play the royal we here. We can like land spacecraft
Speaker 1: in Mars right and like know exactly where it's going
Speaker 1: to land on the planet. That's that's so amazing. It's
Speaker 1: really incredible what we the scientists and engineers have accomplished.
Speaker 1: It's too bad what they messed up on. All right, Well,
Speaker 1: that's the pioneer anomaly, and I guess we can reclassify
Speaker 1: it now, Daniel as a pioneer nomally, or the pioneer
Speaker 1: story or the high precision test of science, that is
Speaker 1: the pioneer spacecraft. That's not as catchy, but maybe more accurate. Again,
Speaker 1: another reminder of how you know vast space is I mean,
Speaker 1: this thing is still within our backyard, just the solar SYSM.
Speaker 1: And even even then, these distances are huge and there's
Speaker 1: a lot that can happen out there when you go
Speaker 1: out into deep space. Yeah, Pioneer ten is more than
Speaker 1: twelve billion kilometers from Earth. It's tens of light hours
Speaker 1: from Earth and moving away really really fast. It's destined
Speaker 1: to reach another star system in about two million years.
Speaker 1: That's sixty seven light years from here. So maybe in
Speaker 1: two million and sixty seven years we'll get a message
Speaker 1: back from the aliens saying thanks for your garbage, Thanks
Speaker 1: for your garbage. With the hot front end, back end,
Speaker 1: it's a hot back end. Let leave, we turn it
Speaker 1: around and let's see if we can turn this around,
Speaker 1: and we'll back into this cultural misunderstanding with the aliens.
Speaker 1: All right, Well, we hope you enjoyed that. Thanks for
Speaker 1: joining us, see you next time. Thanks for listening, and
Speaker 1: remember that Daniel and Jorge explained. The Universe is a
Speaker 1: production of I Heart Radio or more podcast from my
Speaker 1: Heart Radio, visit the I heart Radio app, Apple Podcasts,
Speaker 1: or wherever you listen to your favorite shows. Yeah,