After ten years of operation, NASA has turned off its Galaxy Evolution Explorer (GALEX) space telescope.

After ten years of operation, NASA has turned off its Galaxy Evolution Explorer (GALEX) space telescope.

In a first-of-a-kind move for NASA, the agency in May 2012 loaned GALEX to the California Institute of Technology in Pasadena, which used private funds to continue operating the satellite while NASA retained ownership. Since then, investigators from around the world have used GALEX to study everything from stars in our own Milky Way galaxy to hundreds of thousands of galaxies 5 billion light-years away.

It appears this loan arrangement has now ended because of a lack of funds. Either way, it always baffles me when NASA shuts down a working science telescope merely because it has been operating for a long time. Eventually the space agency will call for a replacement, the building of which will be far more expensive than it would have been to keep the original in operation.

Voyager 1 has found the edge of the solar system to be far more complex than predicted by scientists.

The uncertainty of science: Voyager 1 has found the edge of the solar system to be far more complex than predicted by scientists.

Scientists had assumed that Voyager 1, launched in 1977, would have exited the solar system by now. That would mean crossing the heliopause and leaving behind the vast bubble known as the heliosphere, which is characterized by particles flung by the sun and by a powerful magnetic field.

The scientists’ assumption turned out to be half-right. On Aug. 25, Voyager 1 saw a sharp drop-off in the solar particles, also known as the solar wind. At the same time, there was a spike in galactic particles coming from all points of the compass. But the sun’s magnetic field still registers, somewhat diminished, on the spacecraft’s magnetometer. So it’s still in the sun’s magnetic embrace, in a sense.

Kepler’s planet-hunting predecessor, COROT, has been shut down.

Kepler’s planet-hunting predecessor, CoRoT, has been shut down.

CoRoT suffered a computer failure on November, 2, 2012 and although the spacecraft is capable of receiving navigational commands, the French Space Agency CNES reports it can no longer retrieve data from its 30-centimeter telescope. After a valiant effort to try and restore the computer, CNES announced this week that the spacecraft has been retired. CoRoT’s journey will come to a fiery end as it will be deorbited and it will burn up on re-entry in Earth’s atmosphere.

CoRoT found 32 exoplanets with at least a hundred more candidates still to be confirmed.

The remarkable remains of a most recent supernova.

The remarkable remains of a most recent supernova.

Astronomers estimate that a star explodes as a supernova in our Galaxy, on average, about twice per century. In 2008, a team of scientists announced they discovered the remains of a supernova that is the most recent, in Earth’s time frame, known to have occurred in the Milky Way. The explosion would have been visible from Earth a little more than a hundred years ago if it had not been heavily obscured by dust and gas. Its likely location is about 28,000 light years from Earth near the center of the Milky Way.

Astronomers have found a solar system with six exoplanets, three in the habitable zone.

Worlds without end: Astronomers have found a solar system with six exoplanets, three in the habitable zone.

These planets orbit the third fainter star of a triple star system. Viewed from one of these newly found planets the two other suns would look like a pair of very bright stars visible in the daytime and at night they would provide as much illumination as the full Moon. The new planets completely fill up the habitable zone of Gliese 667C, as there are no more stable orbits in which a planet could exist at the right distance to it.

The planets in the habitable zone are all super-Earths.

Update: you can download and read the science paper here.

NASA has decided that the best use for two space mirrors donated to the space agency by the National Reconnaissance Office (NRO) would be to study either dark energy and extrasolar planets.

NASA has decided that the best use for two space mirrors donated to the space agency by the National Reconnaissance Office (NRO) would be to study either dark energy and extrasolar planets.

There is no funding as yet for either mission, so for the moment the mirrors will remain on the ground, in storage.

Radar images of asteroid 1998 QE2, flying past the Earth today, show that it has its own moon.

Radar images of asteroid 1998 QE2, flying past the Earth today, show that it has its own moon.

When astronomers analyzed radar readings to create their first maps of 1998 QE2, the big asteroid that’s due to sail past Earth on Friday, they were surprised to find that it has a moon twice as big as an ocean liner. 1998 QE2 itself is way bigger: The latest readings from NASA’s Deep Space Network antenna in Goldstone, Calif., are consistent with earlier estimates that the asteroid is about 1.7 miles (2.7 kilometers wide). But the moon is hefty as well. Astronomers estimate its diameter at 2,000 feet (600 meters).

Cassini has found hints of activity coming from the Saturn moon Dione.

Cassini has found hints of activity coming from the Saturn moon Dione.

The spacecraft’s magnetometer has detected a faint particle stream coming from the moon, and images showed evidence for a possible liquid or slushy layer under its rock-hard ice crust. Other Cassini images have also revealed ancient, inactive fractures at Dione similar to those seen at Enceladus that currently spray water ice and organic particles.

Not only can the very fast rotation of neutron stars sometimes speed up suddenly, scientists have now discovered that their rotation can suddenly slow as well.

Not only can the very fast rotation of neutron stars sometimes speed up suddenly, scientists have now discovered that their rotation can suddenly slow as well.

The neutron star, 1E 2259+586, is located about 10,000 light-years away toward the constellation Cassiopeia. It is one of about two dozen neutron stars called magnetars, which have very powerful magnetic fields and occasionally produce high-energy explosions or pulses. Observations of X-ray pulses from 1E 2259+586 from July 2011 through mid-April 2012 indicated the magnetar’s rotation was gradually slowing from once every seven seconds, or about eight revolutions per minute. On April 28, 2012, data showed the spin rate had decreased abruptly, by 2.2 millionths of a second, and the magnetar was spinning down at a faster rate.

Astronomers had a theory which explained the sudden increase in a neutron star’s rotation. They don’t have one yet for why this star slowed.

Scientists have released the first topo map of Titan.

Scientists have released the first topo map of Titan.

Whereas Earth’s tallest mountain towers nearly 9 kilometers above sea level, Titan’s topographic variations are mild: Its highest point is just half a kilometer above the mean and its lowest just 1.7 kilometers below.

Overall the detail here is not very great. None of the instruments on Cassini can see anything smaller than a half kilometer, about 1,500 feet, so the data doesn’t really show us the rough details. Moreover, the best data is spotty, as it has been accumulated by about a hundred Cassini fly-bys, rather than systematically by an orbiting spacecraft.

The impact of a 100 pound meteorite on the Moon in March produced the brightest flash ever recorded.

The impact of a 100 pound meteorite on the Moon in March produced the brightest flash ever recorded.

Anyone looking at the Moon at the moment of impact could have seen the explosion–no telescope required. For about one second, the impact site was glowing like a 4th magnitude star.

Ron Suggs, an analyst at the Marshall Space Flight Center, was the first to notice the impact in a digital video recorded by one of the monitoring program’s 14-inch telescopes. “It jumped right out at me, it was so bright,” he recalls.

The 40 kg meteoroid measuring 0.3 to 0.4 meters wide hit the Moon traveling 56,000 mph. The resulting explosion1 packed as much punch as 5 tons of TNT.

It will be really interesting to see the Lunar Reconnaissance Orbiter images of the impact site, which can’t be taken until the spacecraft passes over the site and can photograph it.

Last Saturday the space telescope Swift detected the most powerful gamma ray bursts ever detected.

Last Saturday the space telescope Swift detected the most powerful gamma ray burst ever detected.

You can see the raw reports of the detection, followed up immediately by a host of other ground-based and space-based observations at this website. Click on the circulars for GRB130427A, starting with circular 14448. When this happened last Saturday I was out camping. When I got home there were dozens of circulars to look at. Based on the data here, this gamma-ray burst was relatively close for a grb, approximately 3.6 billion light years away.

The lingering echo of Comet Shoemaker-Levy in the atmosphere of Jupiter.

The lingering echo of Comet Shoemaker-Levy in the atmosphere of Jupiter.

The Herschel observations, together with heat maps provided by NASA’s Infrared Telescope Facility on Mauna Kea, showed the researchers that the Jovian stratosphere was 20° to 30°F (10° to 15°C) warmer than it would be if completely dry. One question is whether the stratospheric warming results from the gentle, continuous infall of interplanetary dust particles, which would be warmed by sunlight as they linger high up. CavaliĂ© and his colleagues believe IDPs create some of the infrared emission but cannot explain it all. Further, a continuously supplied source would migrate to lower depths, yet most of the emission is too high up, at pressures less than 2 millibars. And while the amount of water is roughly constant across the southern hemisphere, the emission gradually weakens northward until it’s less than half as strong. It’s not simply that Jupiter’s bottom half is hotter — there’s just more water down there. As the researchers note, “At least 95% of the observed water comes from the SL9 comet and subsequent (photo)-chemistry in Jupiter’s stratosphere according to our models, as of today.

Taken together, they conclude, these observations offer “clear evidence that a recent comet … is the principal source of water in Jupiter. What we observe today is a remnant of the oxygen delivery by the comet at 44°S in July 1994.”

In a NASA contest, a nine-year-old has named asteroid 1999 RQ36 after the Egyptian god Bennu.

A rose by any other name: In a NASA contest, a nine-year-old has named asteroid 1999 RQ36 after the Egyptian god Bennu.

1999 RQ36, or Bennu, is an important asteroid for two reasons. First, NASA is sending an unmanned sample return mission to it in 2016. Second, some calculations suggest the asteroid has a 1 in a 1000 chance of hitting the Earth in 2182.

In other naming news, the private space company Uwingu has launched its “Adopt-a-Planet” campaign.

This open-ended campaign gives anyone in the public—worldwide—the opportunity to adopt exoplanets in astronomical databases via Uwingu’s web site at www.uwingu.com. Proceeds from the naming and voting will continue to help fuel new Uwingu grants to fund space exploration, research, and education.

As noted earlier, they are ignoring the IAU’s stuffy insistence that only the IAU can name things in space.

An detailed analysis of the tumbling of the asteroid Apophis, detected by radar observations in January, suggests it will be easier to predict the asteroid’s orbit in the future.

The sky isn’t falling: A detailed analysis of the tumbling of the asteroid Apophis, detected by radar observations in January, suggests it will be easier to predict the asteroid’s orbit in the future.

The gentle but persistent nudging [of the Yarkovsky effect] arises when sunlight is absorbed by a rotating object and then reradiated as heat in some other direction. In particular, if Apophis were spinning retrograde (opposite the way Earth does), then over time its orbit would change in a way that increases the chance of impact in 2036. But now we can rest easy, because Apophis appears to be tumbling as it orbits the Sun. That’s the conclusion reached by a team of telescopic observers who monitored the asteroid’s light curve as it passed near Earth in January. Apophis is spinning around two axes at the same time, implying that any Sun-warmed surfaces are radiating heat in all directions, not just one in particular.

It is very difficult to measure the Yarkovsky effect, thus making it very difficult to precisely calculate the orbits of many near Earth asteroids. In the case of Apophis, however, it appears the astronomers have gotten a good handle on the problem.

Hubble has taken a spectacular close-up image of the Horsehead Nebula.

A horsehead of another color: Hubble has taken a spectacular close-up image of the Horsehead Nebula.

Also, if you want to find out exactly how powerful Hubble is in comparison with both ground-based and other space telescopes, check out the video provided by this press release for the new images by the Herschel Space Telescope of the Horsehead Nebula that were also released today. Herschel, which works in the far-infrared, produces good data and information that Hubble cannot, but its imagery cannot compare.

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