Yu55 Asteroid to pass close to Earth in November, 2011

Humungous asteroid will be closer than moon on November 8, 2011

By Leonard David, SPACE.com Space Insider Columnist

Mark your calendars for an impressive and upcoming flyby of an asteroid that’s one of the larger potentially perilous space rocks in the heavens – in terms of smacking the Earth in the future.

It’s the case of asteroid 2005 YU55, a round mini-world that is about 1,300 feet (400 meters) in diameter. In early November, this asteroid will approach Earth within a scant 0.85 lunar distances.

Due the object’s size and whisking by so close to Earth, an extensive campaign of radar, visual and infrared observations are being planned.

Asteroid 2005 YU55 was discovered by Spacewatch at the University of Arizona, Tucson’s Lunar and Planetary Laboratory on Dec. 28, 2005. En route and headed our way, the cosmic wanderer is another reminder about life here on our sitting duck of a planet


“The close Earth approach of 2005 YU55 on Nov. 8, is unusual since it is close and big. On average, one wouldn’t expect an object this big to pass this close but every 30 years,” said Don Yeomans, manager of NASA’s Near-Earth Object Program Office and the Jet Propulsion Laboratory in Pasadena, Calif.

Yeomans said that with new radar capabilities at Goldstone in California — part of NASA’s Deep Space Network — there is a good chance of obtaining radar imaging of 2005 YU55 down to the 5-meter resolution level. Doing so, he said, would mean obtaining higher spatial resolution of the object than that attained by recent spacecraft flyby missions.

“So we like to think of this opportunity as a close flyby mission with Earth as the spacecraft,” Yeomans told SPACE.com. “When combined with ground-based optical and near-infrared observations, the radar data should provide a fairly complete picture of one of the larger potentially hazardous asteroids,” he said.

Asteroid 2005 YU55 is a slow rotator. Because of its size and proximity to Earth, the Minor Planet Center in Cambridge, Mass., has designated the space rock as a “potentially hazardous asteroid.”


Read full article about asteroids risk on Yahoo News

2012 Transit of Venus viewable June 5th / 6th

The following is an article posted March 1st on the National Geographic NewsWatch website, by Victoria Jaggard.

Astronomy in 2012: Watch a Planet Transit With Your Own Eyes!

If you’ve been following the exploits of NASA’s Kepler spacecraft, you probably already know that the mission finds new planets using what’s called the transit method.

In short, Kepler stares at a bunch of stars and records when there’s a periodic dip in a star’s light caused by an object passing in front. With enough data and some careful followup work, scientists can tell whether the passing object is a planet orbiting the star.

So far, Kepler has confirmed 15 new planets using transits, and an additional 1,200 planetary candidates were recently announced. Next year, people around the world will be able to watch a transit of an Earth-size planet with their own eyes.

OK, fine, I admit—the planet in question is our own Venus. But that’s still pretty cool, because Venus transits are exceedingly rare.


Video of 2004 Venus transit, as seen by NASA’s GOES satellite.


The next one will happen in June 2012, and it’ll be visible from only certain parts of the globe (click map below for full screen view).



[UPDATE: For people on the Americas able to see the transit, you'll be looking in the evening hours of June 5. Viewers in Europe, Africa, Asia, and Australia will be watching the morning of June 6. Sky-watchers who want to see the whole transit from start to finish need to be in eastern Australia, New Zealand, New Guinea, the Philippines, China, Korea, Japan, the western Pacific islands, Hawaii, Russia, Alaska, and northwest Canada.]

When it ends, there won’t be another Venus transit until 2117.

What follows is an edited transcript of a conversation I had last week with National Geographic grantee Jay Pasachoff, an astronomer at Williams College in Massachusetts and an expert on eclipses and transits.

So what does a Venus transit look like from Earth?

The great [German] astronomer Johannes Kepler in the 17th century predicted that there’d be a transit of Venus in 1631, but nobody had any idea at the time how big Venus would look, because they didn’t know how big it was or how far it was away. In fact, the transit in 1631 wasn’t visible from Europe, and we didn’t have telescopes at that time in California, so it took until 1639 before anybody saw a transit of Venus. When it was seen, it was just a huge surprise that there was a black dot about 1/30 the diameter of the sun that moved across the surface of the sun.

Venus can look about the same size as a big sunspot, but it looks perfectly round and regular, whereas a sunspot has dark inner regions and lighter outer regions, the umbra and penumbra. In fact, one can also see transits of Mercury across the face of sun. But Mercury is both smaller than Venus and farther away from Earth—it’s only 1/30 the area of Venus—and it looks less impressive, unless you’re looking with a really good telescope or spacecraft.

When I saw a transit of Venus in 2004, I used my 500mm telephoto lens to take pictures that show a beautiful black dot, whereas in 2006 we went to Hawaii to observe a transit of Mercury, and when I took a picture with the same lens, the dot of Mercury was barely visible and was much smaller than a sunspot that was on the sun at the time.

Why study Venus transits?

In the original studies, Edmond Halley [of Halley's comet fame] figured out a way of calculating how far the sun is away from Earth, and therefore how big the solar system is, by studying a transit of Venus. Measuring the size of the solar system used to be the most important activity in astronomy in the 18th and 19th centuries, so hundreds of expeditions went all over the world to make observations of Venus transits.

[Editor's note: Capt. James Cook was funded by England's Royal Society to sail to Tahiti and observe a Venus transit in 1769, collecting valuable data for astronomers back home, who were not in the viewing path. The 2012 transit will also be visible in the South Pacific, and travel agencies are already pitching trips to Tahiti's black-sand beaches to "follow in Cook's footsteps" during the celestial event ... I think a field trip is in order!]