Category Archives: General

M57 – The Ring Nebula


From — Charles Messier’s Catalog of Nebulae and Star Clusters:
18h 45m 21s (281d 20′ 08″) +32d 46′ 03″(January 31, 1779) `A cluster of light between Gamma & Beta Lyrae, discovered when looking for the Comet of 1779, which has passed it very close: it seems that this patch of light, which is round, must be composed of very small stars: with the best telescopes it is impossible to distinguish them; there stays only a suspicion that they are there. M. Messier reported this patch of light on the Chart of the Comet of 1779. M. Darquier, at Toulouse, discovered it when observing the same comet, and he reports: “Nebula between gamma and beta Lyrae; it is very dull, but perfectly outlined; it is as large as Jupiter & resembles a planet which is fading”.’

The Ring Nebula or M57 is located 2,300 light-years / 0.7 kpc away in the constellation Lyra.  This image was taken by the WFPC2 camera onboard the Hubble Space Telescope in 1998.

More about the Ring Nebula from SEDS.

Image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

Underwater Rover

A rover designed to walk on the bottom of the ice. Eventually such a rover could be used on Europa.

I can see plenty of applications for such a rover here on Earth, even around here locally where we have frozen lakes and rivers in the winter.



Happy Equinox


The September equinox arrived at 08:21 UTC.  Autumn in the north and spring in the south.

The image here came from and is a good depiction of what is going on:  Today the equator at 08:21 UTC of the Earth is pointed right at the center of the sun.  As the Earth travels in its orbit the position of the Sun with respect to the equator changes.  In September the tilt is such that the center of the Sun is moving south.  By late December the Earth has moved sufficiently in orbit the apparent movement stops (the December solstice) and starts going back north.