Astronomers have discovered a previously unknown neighbor to the Milky Way.
Astronomers have discovered a previously unknown neighbor galaxy to the Milky Way.
Tag: science
Schools from Puerto Rico dominated the competition at this past weekend’s Great Moonbuggy Race.
Schools from Puerto Rico dominated the competition at this past weekend’s Great Moonbuggy Race.
Smithsonian researchers have recovered a short recording of Alexander Graham Bell’s voice, made in 1885.
Smithsonian researchers have recovered a short recording of Alexander Graham Bell’s voice, made in 1885.
Opportunity went into safe mode during the communications pause in April when the Sun was between Mars and the Earth.
Opportunity went into safe mode during the communications pause in April when the Sun was between Mars and the Earth.
Mission controllers for Opportunity, which landed on Mars in January 2004, first learned of the issue on Saturday (April 27). On that day, the rover got back in touch after a nearly three-week communication moratorium caused by an unfavorable planetary alignment called a Mars solar conjunction, in which Mars and Earth are on opposite sides of the sun. The Opportunity rover apparently put itself into standby on April 22 after sensing a problem during a routine camera check, mission managers said.
It sounds like this is a recoverable problem and the rover will be back in operation momentarily. Stay tuned.
The Herschel Space Telescope has closed its eye on the universe.
The Herschel Space Telescope has closed its eye on the universe.
After four years of operation, the telescope’s supply of helium coolant has run out, leaving the infrared telescope blind to the sky.
Cassini snaps an amazing image of Saturn’s north pole vortex.
Cassini snaps an amazing image of Saturn’s north pole vortex.
Cassini has imaged meteorites as they crash into Saturn’s rings.
Cassini has imaged meteorites as they crash into Saturn’s rings.
An image of the hot spots of the supergiant red star Betelgeuse.
Astronomers have produced an image of the hot spots of the supergiant red star Betelgeuse.
Three years of Solar Dynamics Observatory images of the Sun — in three minutes.
Three years of Solar Dynamics Observatory images of the Sun — in three minutes.
I’ve posted the video below the fold. It’s quite cool.
Note that these images cover the period when the Sun was ramping up to what was hoped to be a strong solar maximum, when SDO was being designed and built. And though the Sun does appear to be active in these images, it is actually far less active than it has been for solar maximums going back at least a century.
The dismal predictions of the future from the first Earth Day in 1970.
Chicken Little report: The dismal predictions of the future from the first Earth Day in 1970.
I especially like the last two predictions, since I expect them to sooner or later become popular again.
Polar Spirits
An evening pause: Film by Ole Salomonsen.
Link fixed. Sorry about the problem.
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.