Tag: astronomy

Impressive radar images of near-Earth asteroid 2007 PA8 were taken during its recent fly-by of Earth.

8:31 am

Impressive radar images of near-Earth asteroid 2007 PA8 were taken during its recent fly-by of Earth.

The images … reveal possible craters, boulders, an irregular, asymmetric shape, and very slow rotation. The asteroid measures approximately one mile wide (about 1.6 kilometers).

The asteroid poses no threat to Earth. The resolution of the images, however, is astonishing, especially considering it was done by radar.

One comment

The discovery of volcanoes on Io

12:39 pm

discovery image

On March 8, 1979, as Voyager 1 was speeding away from Jupiter after its historic flyby of the gas giant three days earlier, it looked back at the planet and took some navigational images. Linda Morabito, one of the engineers in charge of using these navigational images to make sure the spacecraft was on its planned course, took one look at the image on the right, an overexposed image of the moon Io, and decided that it had captured something very unusual. On the limb of the moon was this strange shape that at first glance looked like another moon partly hidden behind Io. She and her fellow engineers immediately realized that this was not possible, and that the object was probably a plume coming up from the surface of Io. To their glee, they had taken the first image of an eruption of active volcano on another world!

Today, on the astro-ph preprint website, Morabito has published a minute-by-minute account of that discovery. It makes for fascinating reading, partly because the discovery was so exciting and unique, partly because it illustrated starkly the human nature of science research, and partly because of the amazing circumstances of that discovery. Only one week before, scientists has predicted active volcanism on Io in a paper published in the journal Science. To quote her abstract:
» Read more

Leave a comment

Astronomers have found a super-earth exoplanet inside its star’s habitable zone.

6:44 pm

Worlds without end: Astronomers have found a super-earth exoplanet inside its star’s habitable zone.

The planet is large enough that it might be more like Neptune, but if it should have any earth-sized moons they will definitely be capable of supporting life.

Update: The science paper included a wonderful graphic comparing the solar system of this star with that of our own solar system. I have posted this graphic below the fold. HD40307g is the potentially habitable planet.
» Read more

4 comments

A house-sized asteroid will zip past the Earth in February at a distance less than 14,000 miles.

12:43 pm

Chicken Little report: A house-sized asteroid will zip past the Earth in February at a distance less than 14,000 miles.

The asteroid, referred to as 2012 DA14, has a diameter of approximately 45m and an estimated mass of 130,000 tonnes. It was discovered at the start of 2012 and is set to travel between the Earth and our geostationary communication satellites on 15 February 2013. At a distance of just 22,500km this will be the closest asteroid ‘fly by’ in recorded history. Asteroid and comet researchers will be gathering at the University of Central Florida (UCF) in Orlando, U.S., to watch the event, but experts say there is no chance of a collision – this time.

The claim that this is the closest “fly by” in recorded history sounds bogus to me, but because of the size of this asteroid the fly-by will nonetheless be quite interesting. Scientists should be able to get a very good look at 2012 DA14 as it goes by.

Leave a comment

The supermassive black hole in the center of the Milky Way is about to get a snack.

6:16 pm

The supermassive black hole in the center of the Milky Way is about to get a snack.

Update: The recently launched NuStar telescope in July detected its first flare from the central black hole (which by the way is called Sagittarius A* and is pronounced Sagittarius A-star). If the gas cloud produces any fireworks as it whips past the black hole in the coming year then NuStar should see it.

3 comments

Kepler reveals our Sun might be more variable than we imagine

5:13 pm

More exoplanet news: The problems of Kepler.

The article outlines the status — both good and bad — of Kepler in its hunt for Earthlike exoplanets.

I have already reported on Kepler’s failed reaction wheel. It no longer has a backup and needs every reaction wheel it has to keep it pointed in so precise a manner. Thus, the loss of one more wheel will shut the telescope down.

However, I had not been aware that the scientists now need more than twice as much time, eight years instead of three, to do their work, because they have discovered that sunlike stars are far more variable than expected. To quote the article,
» Read more

One comment

Astronomers have discovered that the nearest star to the Earth, Alpha Centauri, has an exoplanet only slightly heavier than the Earth.

3:28 pm

Big news: Astronomers have discovered that the nearest star to the Earth, Alpha Centauri, has an exoplanet only slightly heavier than the Earth.

Alpha Centauri is actually a triple star system, with two sunlike stars in a tight orbit around each other and a third star far out orbiting them both. The exoplanet orbits one of the inner stars every 3.2 days.

More details from Nature here.

One comment

A super Earth, made of diamonds

8:55 am

A super Earth, made of diamonds.

Astronomers also thought 55 Cancri e contained a substantial amount of super-heated water, based on the assumption that its chemical makeup was similar to Earth’s, Madhusudhan said. But the new research suggests the planet has no water at all, and appears to be composed primarily of carbon (as graphite and diamond), iron, silicon carbide, and, possibly, some silicates. The study estimates that at least a third of the planet’s mass — the equivalent of about three Earth masses — could be diamond. “By contrast, Earth’s interior is rich in oxygen, but extremely poor in carbon — less than a part in thousand by mass,” says co-author and Yale geophysicist Kanani Lee.

Leave a comment

A star has gone supernova and astronomers get to see it from the very beginning, and even earlier!

7:05 pm

A star has gone supernova and astronomers get to see it from the very beginning, and even earlier!

The star had erupted several times before but had not produced a real supernova explosion. On September 26 it finally did so. Moreover, astronomers have images of the star prior to any eruption, information that until recently was not available for any supernovae.

Leave a comment
1 … 53 54 55 56 57 … 72