By Eric AdamsPosted 11.02.2009 at 4:10 pm 8 Comments
My first attempt at Jupiter [left] demonstrates why it's a tricky first target--the brightness of the planet against the darkness of space casts a wide dynamic range for the novice to capture. But it's possible, as a photo taken with the same camera provided by the SBIG folks shows [right].
Astrophotography is hard. Astronomically hard. Everything has to be perfect. Your telescope, with camera attached, must track your target in precise synchronization with the rotation of the Earth. It can't shake. It can't even vibrate. You have to nail your camera's exposure settings or you'll be rewarded with an incoherent mess. Your targets are often so dim you can't even see them until after the image has been made, so focusing is a nightmare.
So why try? Because it makes the entities floating in the vastness of the universe much more real than any Hubble wallpaper on your computer desktop can.
NASA’s Messenger spacecraft recently made its third flyby of Mercury, in order to get a gravity boost that will enable it to enter into orbit around Mercury in 2011. Scientists used the close encounter to capture images of Mercury's surface that had never been seen before.
Humans tend to imagine things we don't fully understand in our own image: for instance, we anthropomorphize God, most sci-fi movie aliens are some variation of a biped with two eyes, a nose and a mouth, and every planet Captain Kirk visits has an atmosphere just ripe for human respiration. But science tells us things are rarely so neat and tidy out in the great unknown, and just to prove how weird things can be out there, scientists at Washington University St.
When starlight passes through a planet's atmosphere, certain elements absorb specific wavelengths of light, and these show up as dips in the spectrum.
If aliens are out there, the best shot at finding them—assuming they resemble the life-forms on Earth—is to look for planets like ours. E.T.'s home will probably require an atmosphere to have liquid water and keep out solar radiation, so astronomers search for perfectly sized and situated planets surrounded by blankets of life-supporting gases like oxygen and water vapor. Now they know how to recognize that ideal atmosphere.
For a beautiful demonstration of both magnetic force and gyroscopic motion, let's contemplate the Levitron. This novelty toy (which even now sits on my shelf waiting for a quick spin around the block) consists of a magnetic base upon which you spin a magnetic gyroscope. Both the bottom of the gyroscope and the top of the base contain magnetic north poles, and therefore they repel each other.
However, try as you might, you'll never be able to balance the magnet above the base without spinning the top. Why is this?
Google Voice, which will email you transcripts of your voice messages and provide other services, is either a phenomenally attractive management system, or one of the creepier and more intrusive things I've ever heard of. As of now, there's no clear way that Google is going to monetize this, besides charging for long-distance calls. I'm going to guess it'll be targeted ads, but what form would that come in? Other voicemails?
Also in today's links: celebrating Pi Day, cleaning monkey teeth, Pluto, and more.
The 14-year-long summer on Saturn's southern side is drawing to a close. August 11, 2009, marks the planet's vernal equinox, when Saturn's thin rings line up edge-on with the sun. As this happens, the rings will appear to grow thinner until they completely vanish. Because scattered sunlight won't obscure the view, it's a perfect time for NASA's spacecraft Cassini to answer long-standing questions about Saturn.
Ever-keener detection apparatus leads to the discovery of more and more planets outside our solar system
By Matt RansfordPosted 06.23.2008 at 11:50 am 4 Comments
When it launches in 2009, NASA's Kepler Mission will include the most sensitive detection system ever put into service for discovering exosolar planets. In the meantime, our toolkit on Earth is getting better with each passing year. Astronomers using the High Accuracy Radial velocity Planet Searcher (HARPS) at La Silla Observatory in Chile have discovered three new rocky planets orbiting a single star, all within ten times the size of Earth.
No longer a planet, Pluto is now the namesake of its own class of objects: plutoids
By Matt RansfordPosted 06.16.2008 at 3:10 pm 5 Comments
Pluto took a big hit in the eyes of schoolchildren and amateur astronomers two years ago when the International Astronomical Union (IAU) knocked it out of the rank of planets. Deemed too small and irregularly shaped, and with its orbit in the path of another planet, Pluto was relegated to a new class of "dwarf planets." The reclassification came about as the result of discoveries of bodies beyond Pluto's orbit that are the same size or larger than the icy world. And so Pluto was grouped with those far-out solar-system denizens, along with asteroids close to Pluto's size.