This graphic depiction compares our solar system with a newfound
planetary system, 55 Cancri. The new system has a larger-than-Jupiter-mass
planet in an orbit similar to the orbit of our Jupiter. Another large gaseous
planet orbits closer to 55 Cancri. Image courtesy NASA/JPL.
Cluster of burned-out white dwarf stars as seen by the Hubble Telescope
are 12 to 13 billion years old. Since the first stars formed less than 1 billion
years after the universe began in a big bang, these oldest stars finally give a pretty
precise clock on this universe's age: 13 to 14 billion years. The Earth and its
solar system are 4.5 billion years old. Images courtesy NASA
and H. Richer, University of British Columbia.
A Puzzling star
RX J1856, a star of unknown matter 400 light years from earth. Image courtesy NASA/SAO/CXC/J.Drake et al.
Four hundred light years from earth, the star known as RX J1856 in the constellation Corona Austrina "radiates like a solid body with a temperature of 700,000 degrees Celsius and has a diameter of about 7 miles," according to NASA's Chandra X-Ray Observatory and Hubble Space Telescope data. The startling theory is that the star is collapsed and its matter is denser than nuclear matter, the most dense matter found on earth. Since the star's size is so small, "This raises the possibility that these stars are composed of free quarks or crystals of sub-nuclear particles rather than neutrons. In other words, the neutrons in the puzzling star might have dissolved into an extremely dense soup of 'up,' 'down' and 'strange' quarks to form a 'strange quark star.'"
Five Planets Line Up Over Stonehenge
Jupiter is the brightest point in the upper left. The triangle above one of Stonehenge's horizontal stones is formed by Saturn (left), Mars (top), and Venus (right). Smaller, dimmer Mercury is below and to the right of the triangle. Beginning Monday, May 13, this planetary grouping will be joined by the crescent moon. The last moon and planet line-up like this one was in February 1940.
