Blogs / Bad Astronomy

What must aliens think of us when they pick up our TV signals?

Abstruse Goose decided to figure it out:

I wonder what Lrrr from Omicron Persei 8 would say?

Tip o’ the brain slug to David Woods.

Tonight on Showtime, Penn & Teller take on astrology! You can take a peek at the show online here (with the bad words edited out), or you can watch the show at 10:00 p.m. Eastern time.

I happen to know that a certain Beloved Internet Personality who blogs about astronomy and Doctor Who is on the show briefly as well. Well, it’s probably a good episode anyway, so you should order Showtime and watch it, and buy the DVDs as well.

Bonus ironic pun: the episode is directed by Star Price. Siriusly.

So, if you are totally convinced that astrology actually works, despite an entire Universe of evidence stomping on your face telling you you’re wrong, then you can give P&T a piece of your mind personally, since they’ll be at TAM 7. You can yell at them then… but be prepared to have Penn enthusiastically join that Universe of evidence.

And don’t forget:

[Update: Ken Bowley on Facebook clued me in that the LRO camera has a page where you can see the raw images, and zoom in — WAY in — on the image strips. They have 73 cm resolution, folks. Yikes.]

The Lunar Reconnaissance Orbiter has returned its first images from the Moon! Woohoo!

Check. It. Out!

Whoaaaa.

This image, taken in the Mare Nubium region of the Moon, shows a heavily cratered area. The scale here is amazing: the whole image is 1400 meters across, or just under a mile. That’s like looking out your airplane window… if you were over the frakking Moon! Even in this compressed image (click to embiggen) features just a few meters across are distinguishable. See that perfectly circular crater just to the right and a tad below the middle of the picture? It’s about 60 meters across, just a bit bigger than two tennis courts end-to-end. It would easily fit in a football stadium.

Holy Haleakala.

It’s a little difficult to interpret the image; for example, near the bottom in the middle I thought for a moment I saw a crater chain. I don’t think that’s real; our eyes tend to pick out linear features even when they aren’t there. Too bad, because that would be cool; crater chains form when an asteroid or comet breaks up before it hits, and we do see them on pretty much every cratered object in the solar system. You can also get them near a larger impact, when junk ejected from the crater splashes out and lands nearby.

I guarantee we’ll see lots of such chains as LRO snaps more pictures. Awesome.

Check this one too:

This image has the same scale as the other, and shows a region of low hummocks undulating across the Moon. I don’t have much to say scientifically about this particular picture, but I will say that it is eerily beautiful, and completely enthralling. I wouldn’t mind having that framed over my desk!

So there you go, folks. If you want to explore the Moon, all you have to do is sit back and wait for the images to roll in. And remember: when it settles into its final orbit, the pictures LRO takes will have a resolution of 0.5 meters, or 18 inches!

Wow. I cannot wait to see more.

P.S. If you liked this article, you might like this one as well where I dissect an image of the Moon taken from the space station.

Astronomers have discovered a young binary system where both stars are surrounded by thick disks of material that are in the process of forming planets! And it’s a near thing, too — this system almost didn’t exist at all.

First, the cool image:

On the right is a Hubble Space Telescope image of the two stars (collectively called, weirdly, 253-1536). In the optical, the disk enveloping the star on the left (called 253-53 a, so I’ll just call it Star A) is obvious. It’s dark because it blocks most of the light from the star, which is deeply embedded in the disk and can barely be seen. The star on the right (Star B) has a disk as well, but it’s far smaller than the other star’s disk, and swamped by the light of the star. So the components of this binary are like Jekyll and Hyde: one star is blocked by the dark disk, and in the other the disk is outglared by the bright star.

The image on the left was made using the Submillimeter Array, or SMA. At this wavelength (almost out in the radio part of the spectrum) the warm dust in the disks is bright, and the stars are almost completely dark. The disk on the right becomes obvious. Using some relatively simple math, the mass of the disks can be calculated (basically by measuring the size and brightness of the disks): Star A’s disk on the left has a mass of about 70 times that of Jupiter, and Star B’s disk is about 20 times Jupiter’s mass.

Our entire solar system of planets (that is, everything except the Sun) has roughly twice the mass of Jupiter. So what we’re seeing here is easily enough material to make a fully-fledged system of planets! In fact, this is the very first time a binary star, where both stars are detected in visible light, has been seen where each has a disk capable of making planets.

Very cool. And, actually, rather lucky for these stars. They are located inside the vast Orion Nebula, a star-making factory about 1300 light years from Earth. In the heart of the nebula is a cluster of stars containing extremely massive, hot, and bright stars. The starlight from those beacons is so fierce that it actually disrupts disks around nearby young stars; the ultraviolet light boils away the dust in a process called photoevaporation. As you can see in this image (which I took from the scientific journal paper about these observations) 253-1536 is located about a parsec away (more than 3 light years) from the center of the nebula, sparing it from the harshest effects of those bright stars. Had it been much closer, the disks around the two stars would have boiled away by now.

In a few million years, both these stars may have actual planets orbiting them. Star B is a red dwarf, cool and dim, and it’s not clear what type of star A is. Probably not terribly massive, and I’m guessing somewhat less massive than the Sun.

Imagine what the sky would look like from such a planet! From Star A’s planets, for example, Star B would be an intense red glare in the sky, far far brighter than Venus appears from Earth. The position of the other star in the sky would change slowly as the two stars complete their 4500 year long orbit. And if you look away from the other star, you’d be looking deep into the heart of the nebula, where a dozen or more stars would shine almost as brightly as the Moon does from Earth! And, of course, you’d see the nebula itself stretched across half your sky, glowing red, green, and white.

I would sorely love to see such a thing. Wow. Whatever life that eventually evolves there would be very lucky to get such a view… and they’d have another advantage over us. The two stars of 253-1563 are separated by only about 400 times the Earth-Sun distance, about ten times the distance of Pluto from the Earth. If they really had the will, life there could visit the other system! It would be a technical achievement and difficult to be sure, but we’re almost there ourselves.

Hmph. I do believe I’m jealous of a hypothetical life form that won’t even exist for billions of years, if it ever does! Come to think of it, though, by the time any life there has the tech savvy to build rockets, all those bright stars in the nebula will have long since exploded as supernovae… and worse, at a distance of only a few light years, those titanic explosions will do serious damage to any planets, and in fact could blow away those disks long before planets could form.

So maybe planets never will get a chance to exist there. Wow, again: I went from jealous to sad awfully quickly. But such is life in the Universe. I suppose I should just be glad that we here on Earth are clever enough to create telescopes to give us a view of such a remarkable system, and that allows us to appreciate what we see… and what we’ve got already.

Orbits can be a bit complicated. As the International Space Station orbits the Earth every 90 minutes or so, the Earth is spinning underneath it… and not only that, the orbit of the ISS is tilted by about 50 degrees to the Equator. All of this means that any one spot on Earth doesn’t see the ISS every 90 minutes, and in fact it can be days or weeks between favorable overhead passes.

To help you figure all this out, NASA has created a nifty applet to help you determine when the ISS (and a handful of other satellites, including Hubble) are visible at your location. You can enter your country or zip code and it will tell you when the next visible pass of the ISS occurs. You may have to click "Next Sighting" a few times to get one that’s at a decent time, but keep at it.

ISS and the Shuttle rising over the trees. I shot this picture in 2007.

As it happens, the next week or so yields many favorable overhead passages of the ISS in the US — think of it as a holiday celebration (even though there’s that pesky I in ISS). For me, in Boulder, the next good sighting is on Monday July 6, when it passes very close to directly overhead at 10:17 p.m. (there are a few sooner but they are early in the morning when I tend to be asleep).

This application also provides you with a map of the sky to help you out.

And while it’s nice and all, I still prefer to use Heavens Above, a fantastic resource on the web for satellite passes, sky mapping, and tons more. All you need to do is put in your latitude and longitude as accurately as you can (Google Maps will help there) and it will give you a table of dozens of visible satellite passes, including ISS, Hubble, and a gazillion more.

For you Americans out there, the Fourth of July is a great time for skygazing; even though the Sun doesn’t set until late, a lot of folks will be out after dark anyway. So why not stay outside a few extra minutes and watch the real fireworks?

Hey, I just found out the 109th edition of the Carnival of Space is being held at none other than my friend, fellow TAM speaker, and Hollywood scientist Jennifer Ouellette’s Twisted Physics blog!

Go over there, read about space and astronomy and tell her you say "hi".

My bud Neil Tyson was on Jimmy Fallon’s TV show the other day, and they asked him a series of questions. It’s worth watching:

About some people’s total credulity when it comes to ridiculous doomsday scenarios, Neil says:

It’s a profound absence of awareness of … how nature works. They’re missing some science classes in their training in high school or in college that would empower you to understand and to judge when someone else is basically full of it.

I actually disagree with Neil here; it’s not that students missed that part of science class, it’s that it was never taught in science class to start with. It’s very, very rare that science is taught as a process, as a way of knowing. Instead, it’s taught like a compendium of facts, as dry as a dictionary, and like a dictionary only pulled out when needed. In fact, the methods of science are a way of understanding everything in the whole Universe, and so can be used all the time, whether it’s when you’re deciding to eat a sandwich or when you’re trying to figure out why gamma-ray burst beams are collimated so tightly.

Being skeptical, asking for evidence, examining that evidence, and diagnosing it compared to the whole of learning that goes on around it is the way to go. That’s how you distinguish sense from nonsense. It takes work, and sometimes hard work, but it’s worth it. The prize is understanding.

And I do agree strongly with Neil when he says,

Sceince is basically an inoculation against charlatans.

Yup. One of many, but still the best.