Thursday, June 26, 2008 . 6/26/2008
Bits of Ancient Earth Hidden on the Moon
Some scientists believe that at least one meteorite found in Antarctica preserves evidence of ancient life on Mars. Now, work by a team of English scientists reinforces an earlier suggestion that evidence of life on the early Earth might be found in meteorites on the moon.
The original idea was presented in a 2002 paper by University of Washington astronomer John Armstrong, who suggested that material ejected from Earth during the Late Heavy Bombardment (a period about four billion years ago when the Earth was subjected to a rain of asteroids and comets) might be found on the moon.
Armstrong's suggestion was interesting, but whether a meteor ejected from the Earth might arrive intact on the moon remained an open question.
New research by a team under Ian Crawford and Emily Baldwin of the Birkbeck College School of Earth Sciences used more sophisticated means to simulate the pressures any such terrestrial meteorites might have experienced during their arrival on the lunar surface. This confirmed Armstrong's hypothesis. In many cases, the pressures could be low enough to permit the survival of biological markers, making the lunar surface a good place to look for evidence of early terrestrial life.
Any such markers are unlikely to remain on Earth, where they would have been erased long ago by more than three billion years of volcanic activity, later meteor impacts, or simple erosion by wind and rain.
Labels: Space
2 Comments - Post/view commentsWednesday, February 20, 2008 . 2/20/2008
A total eclipse of the moon tonight is expected to delight skywatchers across the United States and much of the world.
It will be the last total lunar eclipse until 2010.
The easy-to-watch event will play out in several stages as Earth's shadow blocks sunlight from shining on the moon. Weather permitting, the eclipse will be visible from all locations in the United States, according to NASA. Along the Oregon and northern California coasts, the moon will rise during the early stages of the eclipse, however.
When to watch
Eclipses occur only at full moon when the sun, Earth and moon are in a perfect line. Because the moon's orbit around Earth is not perfectly aligned with the plane of Earth's orbit around the sun, eclipses do not occur at every full moon.
The moon will enter Earth's umbral shadow (the full shadow) at 8:43 p.m. ET (that's 7:43 p.m. Central, 6:43 p.m. Mountain and 5:43 p.m. Pacific) on Wednesday, Feb. 20. It will appear as though an ever-larger bite is being taken out of the moon.
Some 78 minutes later, the moon will slip into full eclipse. About 51 minutes later, a bright scallop will appear as the moon starts emerging. It will be completely out of the umbral shadow at 9:09 p.m. Pacific time, which is 12:09 a.m. ET on Thursday morning.
For Europe and Africa, the eclipse is a predawn Thursday event, with the moon starting entry to the umbral shadow at 1:43 Greenwich (or Universal) Time.
What you'll see
Look for the moon to possibly turn red during the total portion of the eclipse. "The exact color that the moon appears depends on the amount of dust and clouds in the atmosphere," according to a NASA statement. "If there are extra particles in the atmosphere, from say a recent volcanic eruption, the moon will appear a darker shade of red."
The redness occurs because while the moon is in total shadow, some light from the sun passes through Earth's atmosphere and is bent toward the moon. The effect is to cast all the planet's sunrises and sunsets on the moon.
Christopher Columbus famously used a blood-red eclipse in 1504 to frighten natives on Jamaica into feeding his crew.
The planet Saturn and the bright star Regulus will form a broad triangle with the moon's ruddy disk, according to Joe Rao, SPACE.com's Skywatching Columnist.
You don't need any special equipment to watch a lunar eclipse. Comfortable chairs and warm clothing are good ideas. A telescope will bring out interesting details of the lunar surface, and even a small telescope will reveal Saturn's stunning rings.
[Source: LiveScience]
Here's to hoping the sky will be clear tonight!
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I just got the book The Demon Haunted World by Carl Sagan. I've only read a few pages so far since I read better at night when everything's quiet, but I can already tell that I'm going to enjoy it a lot. What's sad is that I've noticed it was published in 1996 - the year Sagan died. I often find myself wishing that he could somehow come back to life, because truly, from what I've read he seems to have been a great person. I guess I'm kind of greatful that I was only six when he passed away.. but now I'll have to deal with hearing in the news when the time comes for other great minds such as Richard Dawkins. That's one of the reasons I'd like to go to Oxford - so I could get a chance to meet him [Dawkins]. Of course that'll make it ten times harder for me when he dies, but I'll be kicking myself in the foot for not taking a chance to go to, or at least visit that college.
One of the reviews for Demon Haunted World says that Sagan was very gentle when it came to religion, and that's how I want to be. As I've said in a previous post, it does next to nothing to be intolerant and rude, although for some people that's the only way to get through to them.
Also, looking back at old posts in this blog and at all the books I had on ghosts and astrology, I think it's amazing I managed to come through and be skeptical of everything. It's like a visual time-line of my journey to "enlightenment", I guess you could say. 2 Comments - Post/view comments
