3.
The last night of the trip, two hours from sunrise, we found the Crab Nebula, a big gaseous cloud produced when a star blew up in supernova style and was so bright for days that Chinese observers recorded it in 1054. It left behind in its center a very dense, rapidly rotating star called a neutron star. It sends out a beam only in one direction so as it spins, the beam sweeps across like a lighthouse. When astronomers first picked up the radio signal back in 1968 they thought it was a signal from intelligent beings—people didn’t know the physics of neutron stars at the time.
4.
The picture of the nebula is taken with a special CCD camera attached to the end of a telescope, which can detect single particles of light (photons); the light that produced the picture left the Crab Nebula 6,500 years ago. A telescope is like a time machine—you can only see what happened in the past—depending on how far away the object is (e.g., the sun is eight light minutes away, and when you see the sunset it actually happened eight minutes earlier). As distances go, the Crab is not so far.
5.
We took a picture of the Andromeda galaxy which is about 2.5 million light years away—this means that the light we recorded left Andromeda during the Stone Age on earth. Human-like creatures (hominids) were in Africa but not yet in Europe or North America. The light leaving Andromeda now won’t reach earth for another 2.5 million years.
www.suffolk.edu SUFFOLKARTS+SCIENCES//2010
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