Astronomy Picture Of the Day (APOD)Star Trails in Northern Skies
As the Earth spins on its axis, the sky seems to rotate around us. This motion produces the beautiful concentric trails traced by the stars in this time exposure of the night sky.
Help Map The Moon
You can help map the Moon. Early tomorrow morning (Saturday, September 12) the Moon will occult, or pass in front of, the bright star Aldebaran as viewed from some Southern and Eastern areas of the U.S. as well as regions in the Caribbean Sea, Nova Scotia, Newfoundland, Mexico, and Central America.
Europa: Ridges and Rafts on a Frozen Moon
The large Jovian moon Europa may harbor liquid water beneath its frozen crust. Controversy surrounding this idea has been recently fueled by dramatic images of Europa's surface from the Galileo spacecraft. This alluring...
One of the more prominent craters on the Moon is named Copernicus. Copernicus is a large young crater visible with binoculars slightly northwest of the center of the Moon's Earth-facing hemisphere. Copernicus is distinguished by its size and by the many bright rays pointing out from it.
A Cluster Too Far
Why is this galaxy cluster so red? Nearby clusters have galaxies with colors that are much more yellow and blue. A leading explanation is that this cluster of galaxies lies so far across our universe (z~1) that cosmological time dilation significantly reddens the light.
The Sky Towards Sagittarius
A variety of stars and nebulae can be found towards the constellation of Sagittarius. Dense fields of stars laced with dark lanes of dust crowd this region only a few degrees from the center of our Galaxy.
Mercury, the closest planet to the Sun, remains the most mysterious of the Solar System's inner planets. Hiding in the Sun's glare it is a difficult target for Earth bound observers.
The Pulsar Powered Crab
In the Summer of 1054 A.D. Chinese astronomers reported that a star in the constellation of Taurus suddenly became as bright as the full Moon. Fading slowly, it remained visible for over a year.
Nozomi: Earth and Moon
Japan launched its first mission to orbit Mars, Nozomi (Hope), on July 3rd from the Kagoshima Space Center on the island of Kyushu. Nozomi's goal is to explore the Martian atmosphere and magnetic field as well as regions of the planet's surface and moons.
SGR 1900+14 : Magnetar
On August 27th an intense flash of X-rays and gamma-rays swept through our Solar System. Five spacecraft of the Third InterPlanetary gamma-ray burst Network, Ulysses, WIND, RXTE, NEAR, and BeppoSAX, recorded the high energy...