Bad Astronomy » 10 Things

Happy 20th anniversary, Hubble!

Phil Plait — Fri, 23 Apr 2010 13:00:32 +0000

Tomorrow marks the 20th anniversary of the launch of the Hubble Space Telescope. I spent ten years of my life working on that magnificent machine, from using observations of a supernova for my PhD, all the way to helping test, calibrate, and eventually use STIS, a camera put on Hubble in 1997.

Last year, I published Ten Things You Don’t Know About Hubble, and I don’t think I can really add much to it here. I also have a lot of new readers since then, so I’ll simply repost it now as my tip o’ the dew shield to the world’s most famous observatory.

Introduction

On April 24, 1990, the Space Shuttle Discovery roared into space, carrying on board a revolution: The Hubble Space Telescope. It was the largest and most sensitive optical-light telescope ever launched into space, and while it suffered initially from a focusing problem, it would soon return some of the most amazing and beautiful astronomical images anyone had ever seen.

Ten Things You Don’t Know About Comets

Phil Plait — Tue, 20 Apr 2010 12:00:50 +0000

I love me some comets.

I’ve seen quite a few in my time. Some were faint smudges in a big telescope’s eyepiece, some seen only in distant spacecraft images, and some so bright they were obvious and awesome to my naked eye.

They used to be considered harbingers, omens up for interpretation by mystics and people looking for reasons things happened the way they do. In reality, comets are just a class of objects in our solar system along with planets, asteroids, dust, and one biggish star.

Hmm. Did I say "just"? That’s unfair. They are gorgeous, interesting objects, worthy of study. And 100 years ago today — April 20, 1910 — we got a pretty good look at the most famous of them all, Comet Halley, as it passed the Earth at a distance of just 23 million km (14 million miles). It got so bright that it was obvious even when seen from cities. As geometry would have it, the Earth even passed through the comet’s tail, sparking fears of widespread death (cyanogen was detected in the comet, making people think it would poison them). It was the talk of ...

Ten Things You Don’t Know About Hubble

Phil Plait — Wed, 13 May 2009 11:00:46 +0000

Introduction

[Update (June 21, 2009): This entry won third place in 3 Quark Daily's science blog contest!]

Hubble was designed to be periodically upgraded, and even as I write this, astronauts are in the Space Shuttle Atlantis installing two new cameras, fixing two others, and replacing a whole slew of Hubble's parts. This is the last planned mission, ever, to service the venerable 'scope, so what better time to talk about it?

Plus, it's arguably the world's most famous telescope (it's probably the only one people know by name), and yet I suspect that there are lots of things about it that might surprise you. So I present to you Ten Things You Don't Know About the Hubble Space Telescope, part of my

Ten Things You Don’t Know About Pluto

Phil Plait — Fri, 13 Mar 2009 10:00:19 +0000

But then, that’s why I’m here. Allow me to be your tour guide to infinity. Or the inverse of it, I suppose. Since it’s Halloween this seems appropriate… and my book Death from the Skies! just came out, and there’s lots of ways a black hole can destroy the Earth. Mwuhahahaha.

So below I present ten facts about black holes — the third in my series of Ten Things You Don’t Know (the first was on the Milky Way; the second about the Earth). Regular readers will know a few ...

Ten things you don’t know about the Earth

Phil Plait — Tue, 09 Sep 2008 02:00:32 +0000

Look up, look down, look out, look around.

— Yes, "It Can Happen"

Good advice from the 70s progressive band. Look around you. Unless you’re one of the Apollo astronauts, you’ve lived your entire life within a few hundred kilometers of the surface of the Earth. There’s a whole planet beneath your feet, 6.6 sextillion tons of it, one trillion cubic kilometers of it. But how well do you know it?

Below are ten facts about the Earth — the second in my series of Ten Things You Don’t Know (the first was on the Milky Way). Some things I already knew (and probably you do, too), some I had ideas about and had to do some research to check, and others I totally made up. Wait! No! Kidding. They’re all real. But how many of them do you know? Be honest.

1) The Earth is smoother than a billiard ball.

Maybe you’ve heard this statement: if the Earth were shrunk down to the size of a billiard ball, it would actually be smoother than one. When I was in third grade, my teacher said basketball, but it’s the same concept. But is it true? Let’s see. ...

Ten things you don’t know about the Milky Way Galaxy

Phil Plait — Thu, 13 Mar 2008 03:33:49 +0000

So you’ve lived here all your life — in fact, everyone has — but what do you really know about the Milky Way galaxy? Sure, you know it’s a spiral, and it’s 100,000 light years across. And of course, BABloggees are smarter, more well-read, and better looking than the average population, but be honest: do you know all ten of these things? Really?

Liar.

So let’s see if these really are Ten Things You Don’t Know About the Milky Way Galaxy.

1) It’s a barred spiral.

You might know that the Milky Way is a spiral galaxy, perhaps the most beautiful galaxy type. You’ve seen ‘em: majestic arms sweeping out from a central hub or bulge of glowing stars. That’s us. But a lot of spirals have a weird feature: a rectangular block of stars at the center instead of a sphere, and the arms radiate away from the ends of the block. Astronomers call this block a bar, and, you guessed it: we have one.

Is fact, ours is pretty big. At 27,000 light years end-to-end, it’s beefier than most bars. Of course, space is a rough neighborhood. Who wouldn’t want a huge bar located right downtown?

By the way, the image ...