Comet Hartley 2 was discovered by Malcolm Hartley in Australia in 1986. Hartley is a short-period comet, circling the sun in about 6 and a half years. Hartley's previous passes in 2004 and 1997, among others, were not as notable because the comet did not approach as close to Earth as it will during this apparition. At closest approach to Earth, on October 20, 2010, Comet Hartley will pass 0.12 AU from Earth, or about 11 million miles away. The hope is that Comet Hartley will brighten to about magnitude 5, which would put it within reach of the unaided eye from dark-sky sites for October and November. First start tracking the comet with a telescope or binoculars to make sure you are looking in the right location.
Comet Hartley's Location in October and November
For some reason, much of the information on the web and even in printed sources states briefly that Comet Hartley will be in Cygnus during October, which is not true. Below is a list of stars and clusters that Comet Hartley will be near on different dates as it passes through the northeastern constellations of Cassiopeia, Perseus, Auriga, Monoceros, and Canis Minor, before it begins to fade.
- October 1 - about a degree to the right of Schedar (Alpha Cassiopeiae, the bottom point on the right side of the "W" shape of Cassiopeia)
- October 4 and 5 - about 3 degrees to the right of Ruchbah (Delta Cassiopeiae, the bottom point on the left side of the "W" shape of Cassiopeia)
- October 8 - about a half degree to the upper right of the Double Cluster NGC 869 and 884 in Perseus
- October 9 - less than a degree below the Double Cluster
- October 13 and 14 -about 5 degrees wide left of Mirfak (Alpha Persei, the brightest star in Perseus)
- October 18 - 2 degrees to the lower right of Capella (the bright twinkling star in Auriga)
- October 23 and 24 - about 8 degrees wide left of El Nath (the brightest "horn" star of Taurus the Bull)
- October 27 - about one degree above Mu Geminorum (the 2nd brightest "foot" star in Gemini the Twins)
- October 30 - about one degree left of Alhena (the brightest "foot" star in Gemini the Twins)
- November 1 - passes into Monoceros
- November 6 - passes 6 degrees to the right of Procyon in Canis Minor
Find a map of Comet Hartley's locations here.
Deep Impact Rendezvous with Comet Hartley 2
The space probe Deep Impact plans to pass about 435 miles at its closest on November 4. The Deep Impact mission has already sent out a probe that successfully collided with Comet 9P/Tempel in 2005. Stay tuned for more information on what the project learns about Comet Hartley 2.
Source: NASA/JPL/CalTech Horizons Comet Ephemeris
Kelly Whitt - I have been a professional writer for more than a decade, covering many topics from science-based articles to do-it-yourself home ...
