
Space
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Brief Answers to Cosmic Questions
10 Strange Things About The Universe
NOVA | The Elegant Universe: Pt 1
by John Walker Welcome to Your Sky , the interactive planetarium of the Web. You can produce maps in the forms described below for any time and date, viewpoint, and observing location. If you enter the orbital elements of an asteroid or comet, Your Sky will compute its current position and plot it on the map.
Your Sky
satellite
Hubblecast
NASA Probe Successfully Orbiting Mercury—A First
Launched in 2004, the MErcury Surface, Space ENvironment, GEochemistry, and Ranging mission marks the first time a craft has gone near Mercury since 1975, when NASA's Mariner 10 probe conducted flybys. (Get MESSENGER facts and figures .) For the past six and a half years MESSENGER has been maneuvering itself into an orbital path via so-called gravity assists, using the tugs from flybys of Earth, Venus, and Mercury itself to speed up and alter course. At 8:45 p.m.Neutron stars are ancient remnants of stars that have reached the end of their evolutionary journey through space and time. These interesting objects are born from once-large stars that grew to four to eight times the size of our own sun before exploding in catastrophic supernovae. After such an explosion blows a star's outer layers into space, the core remains—but it no longer produces nuclear fusion. With no outward pressure from fusion to counterbalance gravity's inward pull, the star condenses and collapses in upon itself. Despite their small diameters—about 12.5 miles (20 kilometers)—neutron stars boast nearly 1.5 times the mass of our sun, and are thus incredibly dense.

