Tuesday 18 August, 2009

Send a Tweet to our Alien Friends on Gliese 581 D

If you've ever wanted to communicate with aliens, here's your chance. Cosmos Magazine is offering the chance to send a message to another planet, Gliese 581 d. This exoplanet is about 20.3 light-years from Earth, in the constellation Libra, and some have said if life is elsewhere in the Universe, this is the mostly likely place that we currently know about. It was first discovered in 2007, and astronomers say this planet is well within the habitable zone around its star, where liquid water oceans could exist. Cosmos is collecting short, 160 character messages to be transmitted out to the vicinity of Gliese 581 d with the Canberra Deep Space Communication Complex in Tidbinbilla, Australia. Cosmos says it will take about 20 years for the message to reach its destination, and admits there is no guarantee of a response. If interested, check out Cosmos' "Hello From Earth" webpage. Hurry, as the deadline is 5pm Monday August 24, 2009 Sydney time (07:00 GMT Monday 24 August 2009).This is Cosmos' way of celebrating the IYA and National Science Week in Australia. However, we've had lively discussions here on before UT about if we are sending too much information out into the cosmos. What do you think?

2000 Sols on Mars

Another milestone for the Mars Exploration Rovers: Spirit has been operating on Mars for 2000 sols, or Martian days. Who would have ever thought the rovers would last this long? But here they are, still going, um, pretty strong. Even though she's got plenty of electrical power, Spirit is currently stuck in loose soil at her location, called Troy. But engineers are working hard to figure out how to set her free. Check out the latest on the efforts at the Free Spirit website. To celebrate Spirit's milestone, Unmanned Spaceflight's Astro0 has put together a Sol 2000 poster over at his website, Astro0 in Space. It's gorgeous, and includes a new poem by my pal Stuart Atkinson, so check it out!

Return of the Mars Hoax

For the sixth year in a row, a message about the Red Planet is popping up in email boxes around the world. It instructs readers to go outside after dark on August 27th and behold the sky. "Mars will look as large as the full moon," it says. "No one alive today will ever see this again."
Don't believe it.Here's what will really happen if you go outside after dark on August 27th. Nothing. Mars won't be there. On that date, the red planet will be nearly 250 million km away from Earth and completely absent from the evening sky.
The Mars Hoax got its start in 2003 when Earth and Mars really did have a close encounter. On Aug. 27th of that year, Mars was only 56 million km away, a 60,000-year record for martian close approaches to Earth. Someone sent an email alerting friends to the event. The message contained some misunderstandings and omissions—but what email doesn't? A piece of advanced technology called the "forward button" did the rest.Tolerant readers may say that the Mars Hoax is not really a hoax, because it is not an intentional trick. The composer probably believed everything he or she wrote in the message. If that's true, a better name might be the "Mars Misunderstanding" or maybe the "Confusing-Email-About-Mars-You-Should-Delete-and-Not-Forward-to-Anyone-Except-Your-In-Laws."Another aspect of the Mars Hoax: It says Mars will look as large as the full Moon if you magnify it 75x using a backyard telescope. The italicized text is usually omitted from verbal and written summaries of the Hoax. (For example, see the beginning of this story.) Does this fine print make the Mars Hoax true? After all, if you magnify the tiny disk of Mars 75x, it does subtend an angle about the same as the Moon.
A good reference is the Moon Illusion. Moons on the horizon look huge; Moons directly overhead look smaller. In both cases, it is the same Moon, but the human mind perceives the size of the Moon differently depending on its surroundings. Likewise, your perception of Mars is affected by the planet's surroundings. Locate the planet at the end of a little dark tunnel, and it is going to look tiny regardless of magnification.

Amino Acid Found in Stardust Comet Sample


NASA scientists studying the comet samples returned by the Stardust spacecraft have discovered glycine, a fundamental building block of life. Stardust captured the samples from comet Wild 2 in 2004 and returned them to Earth in 2006. "Glycine is an amino acid used by living organisms to make proteins, and this is the first time an amino acid has been found in a comet," said Dr. Jamie Elsila of NASA's Goddard Space Flight Center. "Our discovery supports the theory that some of life's ingredients formed in space and were delivered to Earth long ago by meteorite and comet impacts."Proteins are a major component of all living cells, and amino acids are the building blocks of protein. Just as the 26 letters of the alphabet are arranged in limitless combinations to make words, life uses 20 different amino acids in a huge variety of arrangements to build millions of different proteins.As Stardust passed through dense gas and dust surrounding the icy nucleus of Wild 2 (pronounced "Vilt-2"), special collection grids filled with aerogel – a novel sponge-like material that's more than 99 percent empty space – gently captured samples of the comet's gas and dust. The grid was stowed in a capsule which detached from the spacecraft and parachuted to Earth on January 15, 2006. Since then, scientists around the world have been busy analyzing the samples to learn the secrets of comet formation and our solar system's history.