Showing posts with label Astronomy. Show all posts
Showing posts with label Astronomy. Show all posts

Tuesday, March 4, 2008

Crash!

This just in!

NASA's Mars Reconnaissance Orbiter caught the first ever image of active avalanches on Mars. They're near the Red Planet's north pole and show tan clouds billowing away from the foot of a slope where ice and dust have just fallen down.

Candice Hansen, the deputy principal investigator for the camera (called HiRISE) said, "we were checking for springtime changes in the carbon-dioxide frost covering a dune field, and finding avalanches was completely serendipitous."

Get the full story here.

Saturday, March 1, 2008

Dirty Space

Apologies for not posting yesterday like promised. Got stuck in Ikea and then in traffic between DC and Baltimore. Ew.


In the universe, patterns seem to repeat themselves but on different scales. This is what I thought when I saw this story. Astronomers at the Carnegie Institution have discovered that space may be filled with tiny “whiskers of carbon.” We can’t just wipe this carbon away with a paper towel, so this is dimming the light of far-away objects like Type 1a supernovae.

Now, Type 1a supernovae are the super important “standard candles” in cosmology. Astronomers use them to gauge distances in space. They’re called standard candles because they are so predicable that they can be used as measurement tools. When astronomers discovered a hic-up in their measurement scheme, they came up with dark energy, and the universe’s expansion to explain it.

Andrew Steele and Marc Fries of the Carnegie Institution’s Geophysical Laboratory published a paper that shows their discovery of a new form of carbon that date from the formation of the solar system. Their carbon was produced by the sun, and so they hypothesize that the same kind could be produced and spread out into space by supernovae explosions. This would mess up measurements of the supernovae.

Currently, the researchers are not commenting on what this could mean for the dark energy hypothesis. They will feed the information into NASA and ESA (European Space Agency) missions that look for the effects of dark energy in order to understand its impact on dark energy models.

Back to what I mentioned about repeating patterns: In my research at Oberlin, I was in the “pulsar lab”. Really, we were using pulsars, or pulsating dead stars (another “standard candle”), to study the interstellar medium. I was part of the team that studied these patterns in the dust between the pulsars and us. This had huge implications, of course, because dozens of teams of scientists use pulsars to study space. If we could find a way to subtract this dust from the observations, then you could get a clearer, brighter signal.

The scales are different; our pulsars were within our galaxy, and pretty close to us in space terms. But these guys are talking about supernovae and universe expansion, which is on a far larger scale. But if you think about it, it makes sense. You can’t just have a whole lot of empty space out there, right? Just because something doesn’t emit light doesn’t meant it’s not out there. Space is really, really, really large and scientists are just starting to notice the not-so-sexy things like dust and carbon between the sexy stuff like supernovae and pulsars. But it’s the little stuff that can tell us how life formed. Right now, building life seems so impossible, but is that because we don’t even know what’s out there?

Tuesday, February 26, 2008

Purdy Pic for the Night

I'll write the Enceladus story or something even cooler later in the week, but tonight I thought I'd post a nice picture from NASA. Tonight's image was taken from the Swift satellite. They made it by combining 39 frames together over 11 hours of exposure time. This is the nearby “Triangulum Galaxy” and is in the ultraviolet light range (the galaxy is purple only if we could see in ultraviolet). It’s about 2.9 million light-years from Earth in the constellation Triangulum.
Go here for a better image:
http://www.nasa.gov/images/content/214434main_M33_UVOT.jpg
And for more of the story:
http://www.nasa.gov/mission_pages/swift/bursts/m33.html