Blogs / Bad Astronomy

Panspermia is the idea that life on Earth originated in space and was seeded here by some event. This covers a lot of ground sky: comets, Mars, Venus, aliens, and so on.

The idea isn’t as far-fetched as it sounds. It’s more medium-fetched. Mars is smaller and farther from the Sun, so therefore it cooled faster than Earth did after the period of heavy asteroid and comet bombardment a billion or so years after the planets formed. It may have had oceans and better conditions for the start of basic life before the Earth had cooled enough.

But if life started up first on Mars, how did it get here?

Asteroid impacts. The idea is that a smallish asteroid could have hit Mars and launched quite a bit of Martian territory into space. Eventually this could hit Earth. We know this can happen; we have samples of meteorites that are clearly form Mars; the isotope ratios of the chemicals in the meteorites matches what we know of Mars’s atmosphere. Heck, I used to own a small Mars meteorite myself, until it fell out of my bag and I lost it, arrrrggggg!

Anyway, if some of that Martian ground had bugs in it of the protozoan kind, then they could make it to Earth.

Of course, there are hazards. They’re in space a long time, so they have to survive that. They also have to survive the fall to Earth. It’s not clear they could live through either event. And before that, they have to survive the enormous pressure of being smacked by an asteroid impact.

But a new paper that just came out in the peer-reviewed journal Astrobiology says that some bacteria could, in fact, survive the initial launch event. Amazingly, the enormous pressure generated in an asteroid impact on the surface of Mars may be survivable, if you’re really really tiny.

The researcher made models of the Martian ground seeded with bacteria, then subjected these samples to the pressures expected in an impact event. Amazingly, many of the bacteria survived. Lichens and bacteriospores did the best, surviving pressures from 5 - 40 billion Pascals, which is about 50,000 to 400,000 atmospheric pressures. That’s a lot. Cyanobacteria were the wussies of the lot, only surviving up to 100,000 atmospheric pressures.

Mind you, a human would be less than a greasy smear at that kind of pressure.

Anyway, this is pretty interesting stuff. It doesn’t say that the buggers could survive the trip here (millions of years) and the entry into our atmosphere, but there are scenarios where those are possible.

On a personal note, I think panspermia is interesting and worth investigating, but some people think it’s the panacea to everything. Notably an astronomer named Chandra Wickramasinghe, who has made the fun claims that interstellar dust is actually made of clouds of E. coli, and that the flu is really a virus from space.

Right.

Still, when the study stays scientific, it’s worth a look. I have seen no evidence at all that we actually did start on Mars or a comet or Somewhere Else, but it’s still possible such evidence will turn up. When we get to Mars, for example, what if we find DNA-based life? It’s much easier to get a rock from Mars to Earth than vice-versa (due to orbital and gravitational mechanics), so a find like that would be pretty conclusive. Until then, we have to do what we can to figure out what it was like for such interplanetary interlopers each step of the way. And the first step appears to be viable.

Oh– I cover some of this in my upcoming book, too. After all, if bugs might have made it here three billion years ago, they might make it today. Can we get wiped out by alien bacteria? Well, no, but read the book anyway.

Tip o’ the Whipple Shield to SpaceRef.

Back in 2004, European astronomers announced evidence of a tremendously distant galaxy, discovered only because its light was magnified and brightened by a gravitational lens. If this pans out (it appears that it’s still unconfirmed) it would be the most distant galaxy ever detected, a numbing 13.2 billion light years away.

Being rational, I didn’t realize is how much cooler this news really is: it’s actually evidence of a vast alien civilization artificially engineering galaxies!

I have no idea how I missed this.

I mean, it’s so obvious:

Intervention was needed by the Type IV civilization that created the big bang in their massive inter-universe particle colliders. The big bang created a black hole in the hyperspace – our universe with three spatial dimensions and a forward moving single time dimension. According to scientists this was the start of ‘dark ages’ that was eventually corrected through the intervention of the Type IV civilization.

Hmmm, "according to scientists", it says. I’m really sorry the article didn’t give their names. I sure would like to talk with them! C’mon, if they know about black holes in hyperspace then I would love to chat with them over a few drinks. Or a few hundred, maybe. After reading that whole article I doubt I have many brain cells left to kill anyway.

Tip o’ the tin foil beanie to Fark and the dozen or two BABloggees who sent this to me.

You may have already heard that scientists have decided that is it time for the solar satellite Ulysses to shed this mortal coil.

Ulysses was launched from the Space Shuttle back in 1990, and was designed to operate for 5 years. Now, over 17 years later, its radioactive power source has finally decayed to the point where power is a serious issue. They’ve decided that in a few months they’ll shut it off, after an extraordinary mission.

Ulysses didn’t take pictures, so you may never have heard of its breakthrough science. It was the first machine to directly detect interstellar dust particles and helium atoms in our solar system, literally, interlopers from another star. It took unprecedented data of the Sun and its magnetic field, and did so continuously for so long that we now have an excellent baseline for such measurements, including over an entire sunspot cycle^*.

For me, the most interesting aspect of the mission was that it was in a solar polar orbit: instead of sticking to the orbital plane of the planets like most probes, it was actually sent into an orbit nearly perpendicular to the orbit of the planets, so that it could peer straight down over the solar poles, an aspect we had never witnessed before.

Getting a probe into an orbit like this is hard. Why? Because the Earth orbits the Sun pretty quickly, at 30 km/s (18 miles/second). You need to mostly negate that velocity for a probe to end up perpendicular to the plane of Earth’s orbit, and then you need to give it a huge velocity "down", south if you will, to get it in that orbit (or up, of course, but in this case Ulysses was sent down). No rocket we have now (or in 1990) could do that.

So we borrowed energy from one of the biggest sources we have: Jupiter. Ulysses was launched toward the giant planet, and using a slingshot maneuver launched itself down, down, and away, into the polar orbit around the Sun. While it was at Jupiter it took lots of scientific measurements, and has been sending back data ever since.

But now that’s over. With the power source dying, it cannot keep energy flowing to its instruments, communication devices, and also be able to heat the hydrazine fuel it uses for maneuvering (this is the same stuff the spysat that was recently destroyed — and many other satellites — use for fuel). When Ulysses’s orbit takes it out to Jupiter’s distance once again, it’s so cold that the probe has a hard time keeping its fuel from freezing. All of these together mean it’s time for Ulysses to say its goodbyes.

My only regret for this mission? It didn’t swing by the asteroid 201 Penelope.

^*Pedantically, you could say it’s half a cycle since the Sun’s magnetic field reverses every 11 years, and therefore a full cycle is 22 years. But it’s a full sunspot cycle of minimum numbers of sunspots to maximum and back to minimum, so that counts.

NASA’s Swift observatory is designed to detect high-energy radiation coming from the most powerful explosions in the Universe: gamma-ray bursts.

But it’s also equipped with a more normal telescope, one that has a 30 centimeter mirror — that’s smaller than the one I have in my garage! But, this telescope is in space, so the atmosphere doesn’t blur out the images. More importantly, the air above our heads absorbs ultraviolet light, preventing ground-based telescopes from even seeing any UV light.

So Swift’s UVOT (Ultraviolet/Optical Telescope) may not be big, but it can easily see UV coming from astronomical objects. And it has a wide field of view, allowing it to get fantastic images of bigger things… like galaxies.

That’s M33 (click to embiggen), a very nearby galaxy; it’s part of our neighborhood of galaxies called the Local Group. It’s a hair under 3 million light years away, and it’s smaller than the Milky Way, about half our size and a tenth our mass. It’s actually visible with binoculars as a fuzzy patch not too far from its big brother, the Andromeda galaxy.

The funny thing is, we know that UV light is predominantly given off by star-forming regions in galaxies; gas clouds where stars are actively being born. The amount of UV from M33 indicates that it is ablaze with stars, cranking them out at a rate far higher than the Milky Way. So even though it’s a bit on the smallish side, it’s certainly pulling its weight when it comes to making stars.

This image is pretty cool. It’s a mosaic of 39 individual images totaling 11 hours of exposure time, using three different UV filters, and it’s the most detailed UV image of an entire galaxy ever taken. Not bad for a telescope built to do an entirely different kind of science!

I worked on the education and public outreach for Swift for several years, and I remember first reading about the UVOT and thinking, wow that’s a pretty small telescope. I wonder what it will be able to do? Then after a moment or two of some mental math I began to realize that this was in fact a fairly powerful telescope; it’s no Hubble, but it can do some terrific science. And it can also make some very pretty pictures.

I am a little green, I suppose. I turn off lights when I leave the room, try to think of ways of eating up less power, and so on.

I like the idea of windmills, though only for small use; having a farm of them doesn’t make a lot of sense because the losses are so great when you try to pump the electricity from the farm (generally remotely located) to where it’s needed — I learned about this from a Berkeley researcher, before you accuse me of being a neocon or anything. From what I can tell, wind power is better on an individual basis, like solar cells on a house.

But living here near the Colorado front range, where we get scary screamingly-fast chinooks, I don’t think I want a windmill for my house. And I have video evidence of why.

Yikes. I mean, yikes.

Tip o’ the windbreaker to Dan Durda.