M45: The Pleiades Star Cluster
Astronomy Picture of the Day
Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters. The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. Quite evident in the above photograph are the blue reflection nebulae that surround the brighter cluster stars. Low mass, faint, brown dwarfs have also been found in the Pleiades.
By Antonio Fernandez-Sanchez
Attacking Mars
Astronomy Picture of the Day
The Spirit rover attacked Mars again late last month. What might look, above, like a military attack, though, was once again just a scientific one - Spirit was instructed to closely inspect some interesting rocks near Columbia Hills. Spirits Front Hazard Avoidance Camera captured the rover's Instrument Deployment Device above as it guided the Microscopic Imager to get a closer look at a rock dubbed Breadbox. Images taken by the Microscopic Imager show a rock surface consistent with basalt corroded by ancient groundwater. Structures with similar origins can be found, for example, in the Western Desert of Egypt on Earth. The above picture taken on June 30, the 175th Martian day that the Spirit rover has been on the red planet.
Shuttle Engine Blast
Astronomy Picture of the Day
A Solar Eclipse Painting from the 1700s
Astronomy Picture of the Day
Is this painting the earliest realistic depiction of a total eclipse of the Sun? Some historians believe it is. The above painting was completed in 1735 by Cosmas Damian Asam, a painter and architect famous in early eighteenth century Germany. Clearly drawn is not only a total solar eclipse, but the solar corona and the diamond ring effect visible when sunlight flows only between mountains on the Moon. The person depicted viewing these eclipse phenomena is St. Benedict. Roberta J. M. Olson and Jay Pasachoff have hypothesized that Asam himself may have seen first hand one or all of the total solar eclipses of May 1706, 1724, and 1733. Many facts about our astronomical universe that are taken for granted today have been known -- or accurately recorded -- only during the last millennium. Asam's painting currently hangs in Weltenburg Abbey in Bavaria, Germany.
By Jay Pasachoff
Arp 230: Two Spirals in One?
Astronomy Picture of the Day
Is this one galaxy or two? Analysis of Arp 230 has shown evidence that this seemingly single spiral galaxy is actually the result of the recent collision of two spiral galaxies. The slow motion collision took place over about 100 million years and induced a burst of star formation that has begun to subside. The collision apparently had many similarities to the colliding galaxy sequence in the IMAX movie "Cosmic Voyage."
M45: The Pleiades Star Cluster
Astronomy Picture of the Day
Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters. The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. Quite evident in the above photograph are the blue reflection nebulae that surround the brighter cluster stars. Low mass, faint, brown dwarfs have also been found in the Pleiades.
By Antonio Fernandez-Sanchez
Attacking Mars
Astronomy Picture of the Day
The Spirit rover attacked Mars again late last month. What might look, above, like a military attack, though, was once again just a scientific one - Spirit was instructed to closely inspect some interesting rocks near Columbia Hills. Spirits Front Hazard Avoidance Camera captured the rover's Instrument Deployment Device above as it guided the Microscopic Imager to get a closer look at a rock dubbed Breadbox. Images taken by the Microscopic Imager show a rock surface consistent with basalt corroded by ancient groundwater. Structures with similar origins can be found, for example, in the Western Desert of Egypt on Earth. The above picture taken on June 30, the 175th Martian day that the Spirit rover has been on the red planet.