SpaceJibe

March 6, 2009

Spacecraft to blast off in search of ‘Earths’

Kepler will look for planets passing in front of their parent stars. Such events are called transits.

Kepler will look for planets passing in front of their parent stars. Such events are called transits.

Calling it a mission that may fundamentally change humanity’s view of itself, NASA on Friday prepared to launch a telescope that will search our corner of the Milky Way galaxy for Earth-like planets.

The Kepler spacecraft is scheduled to blast into space on top of a Delta II rocket from Cape Canaveral Air Force Station in Florida just before 11 p.m. ET.

“This is a historical mission. It’s not just a science mission,” NASA Associate Administrator Ed Weiler said during a pre-launch news conference.

“It really attacks some very basic human questions that have been part of our genetic code since that first man or woman looked up in the sky and asked the question: Are we alone?”

Kepler contains a special telescope that will stare at 100,000 stars in the Cygnus-Lyra region of the Milky Way for more than three years as it trails Earth’s orbit around the Sun.

The spacecraft will look for tiny dips in a star’s brightness, which can mean an orbiting planet is passing in front of it — an event called a transit.

The instrument is so precise that it can register changes in brightness of 20 parts per million in stars that are thousands of light years away.

“Being able to make that kind of a sensitive measurement over a very large number of stars was extremely challenging,” Kepler project manager James Fanson said.

“So we’re very proud of the vehicle we have built. This is a crowning achievement for NASA and a monumental step in our search for other worlds around other stars.”

NASAs Kepler spacecraft is placed on a stand for fueling. The telescope will be launched aboard a Delta II rocket.

NASA's Kepler spacecraft is placed on a stand for fueling. The telescope will be launched aboard a Delta II rocket.

Are we alone?

The $600 million mission is named after Johannes Kepler, a 17th-century German astronomer who was the first to correctly explain planetary motion. His discoveries combined with modern technology may soon help to answer whether we are alone in the universe or whether Earth-like worlds inhabited by some type of life are common.

“We won’t find E.T., but we might find E.T.’s home,” said William Borucki, science principal investigator for the Kepler mission.

About 330 “exoplanets” — those circling sun-like stars outside the solar system — have been discovered since the first was confirmed in 1995.

Most are gas giants like Jupiter, but some have been classified as “super earths,” or worlds several times the mass of our planet, said Alan Boss, an astronomer with the Carnegie Institution who serves on the Kepler Science Council. They are too hot to support life, he added, calling them “steam worlds.”

Europe’s COROT space telescope caused a stir last month when it spotted the smallest terrestrial exoplanet ever found. With a diameter less than twice that of Earth, the planet orbits very close to its star and has temperatures up to 1,500° Celsius (more than 2,700° Fahrenheit), according to the European Space Agency. It may be rocky and covered in lava.

Scientists have marveled how strange some of the alien worlds are.

“The density of these planets has been astounding,” Borucki said. “We’re finding planets that float like a piece of foam on water, [with] very, very low densities. We’re finding some planets where the densities are heavier than that of lead.”

The Kepler telescope, however, is seeking something much more familiar: Earth-like planets with rocky surfaces, orbiting in their stars’ habitable, or “Goldilocks,” zones — not too hot or too cold, but just right for liquid water to exist.

  This image shows part of the Milky Way region of the sky where the Kepler spacecraft will be pointing.

This image shows part of the Milky Way region of the sky where the Kepler spacecraft will be pointing.

Quest for a ‘pale blue dot’

Once Kepler spots a planet, scientists will be able to calculate its size, mass, orbital period, distance from star and surface temperature, Boss said. He called the mission a “step one” that will tell astronomers how hard it is to find nearby habitable worlds.

“Once we know how many there really are … then NASA will be able to build space telescopes that can actually go out and take a picture of that nearby ‘Earth’ and measure the elements and compounds in its atmosphere of the planet and give us some hint as to whether or not it’s got life,” Boss said.

Boss believes that there may be 100 billion Earth-like planets in the Milky Way, or one for every sun-type star in the galaxy. He said scientists should know by 2013 — the end of Kepler’s mission — whether life in the universe could be widespread.

The 20-year goal is to someday take a picture of a pale blue dot orbiting a nearby star, said Debra Fischer, an astronomy professor at San Francisco State University, during a NASA news conference.

Boss called it a potentially unprecedented time of discovery for scientists.

“Sometimes, people call this the golden age of astronomy. I think it’s more like the platinum age of astronomy. It’s beyond gold,” Boss said.

Source

March 4, 2009

Uh, We Almost Got Asteroided Yesterday

Filed under: Asteroids, Inner Solar System — bferrari @ 10:31 am

Gizmodo

A 30-50 meter-wide asteroid just passed seven times closer to us than the moon, glowing so bright you could see it through a cloud. If it had hit the ocean, it would have tsunamied.

The Sydney Morning Herald says that if it had been headed toward a populated part of the world, we would have had 24 hours to act and evacuate. Sky and Telescope says that it was about twice the altitude of our communications satellites.

To put it into perspective, here’s io9’s list of scariest asteroid attacks on Earth, not including this one.

It would have looked somewhat similar to this, the great daylight fireball of 1972. How do we know that wasn’t Kal-El? [SMH and NasaImage credit to the original artist]

Source

March 2, 2009

‘Cosmic Eye’ Photographed Staring Across Space

Filed under: Outer Solar System, Supernova — bferrari @ 10:31 am
The Helix Nebula, NGC 7293, as spotted by the Wide Field Imager at the European Southern Observatory in Chile. (ESO)

The Helix Nebula, NGC 7293, as spotted by the Wide Field Imager at the European Southern Observatory in Chile. (ESO)

The Times

A spectacular “cosmic eye” has been photographed in space by a telescope in Chile, showing a distant nebula in which sunlike stars are burning themselves out.

The image of the Helix nebula, which lies 700 light years away in the constellation Aquarius, was captured with the Wide Field Imager instrument at the La Silla Observatory high above the Atacama Desert.

The Helix is a planetary nebula — a kind of stellar old people’s home, in which stars at the end of their lives shed clouds of gas, often creating intricate patterns that shine with great beauty.

The Helix nebula is one of the closest planetary nebulae to Earth, but it is hard to see visually because its light is spread thinly over a large area of sky, a quarter of the size of the full Moon.

The main ring of the Helix nebula is about two light-years across, or half the distance between the Sun and the nearest star.

Around the inside of the ring, it is possible to see small blobs that resemble droplets of water, known as “cometary knots,” which have faint tails that extend away from the central star.

Source

Spacecraft Sees Spectacular Solar Eclipse on Moon

Filed under: Inner Solar System — bferrari @ 10:28 am
A still of the Kaguya/Selene probes high-definition video of the solar eclipse seen from the moon. (JAXA)

A still of the Kaguya/Selene probe's high-definition video of the solar eclipse seen from the moon. (JAXA)

Monday, March 02, 2009

There was a solar eclipse earlier this month — but it wasn’t visible anywhere on Earth.

Rather, a Japanese space probe in orbit around the moon got spectacular high-definition video of the sun being blocked — by the Earth, producing an otherworldly “diamond-ring” eclipse.

It may be only the third time such an eclipse has been viewed by terrestrials, human or otherwise.

An American lunar lander got a blurry snapshot of a solar eclipse in 1967, and two years later Apollo 12 astronauts got treated to the same thing on their way back from the moon.

The Kaguya, or Selene, probe was traveling from the dark to the light side of the moon on Feb. 9.

The sun rose over the moon’s surface, as usual, but on Feb. 9 it was just a thin ring surrounding darkness.

(The Earth’s disk is a bit smaller than the sun’s when viewed from the moon; on Earth, the moon just about covers the sun.)

In the video, only a small semi-circle is visible at first as the sun rises over the horizon.

The sun being eclipsed by the Earth in a photo taken by the Apollo 12 mission in November 1969. (NASA)

The sun being eclipsed by the Earth in a photo taken by the Apollo 12 mission in November 1969. (NASA)

The circle quickly expands, but before it’s complete the sun suddenly breaks forth from the lower right corner of the circle, filling the screen with light.

• Click here to watch the video.

• Click here for the Japan Aerospace Exploration Agency (JAXA) press release.

• Click here for a longer press release from NASA.

Source

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