#OTD in 1877 American astronomer Asaph Hall discovers Phobos, innermost moon orbiting Mars. It took the U.S. Naval Observatory’s giant 26-inch telescope to located tiny Phobos, whose mean radius is less than 7 miles.
Interestingly, Phobos is slowly spiraling closer to Mars, and will impact the plant in less than 100 million years.
Courtesy of NASA
Make your evening plans… head outside tonight about an hour after sunset and look southwest for two bright objects: ruddy Mars and brilliant blue-white Spica. The pair will be close, really close… less than 2 degrees apart! Saturn too, is lurking, about 12 degrees away at 10 o’clock from the Mars-Spica pairing. Enjoy.
#OTD in 2000, the Russian Zvezda Service Module was launched from the Baikonur Cosmodrome in Kazakhstan, en route to the #ISS. The 40-plus foot module currently provides much-needed living quarters, life support, communications, and a docking station.
In related news, #Today is the 5,000th day humans have been aboard #ISS.
#OTD… July 9, 1979, Voyager 2 officially passes Jupiter on its way to visit the other three gas giants – Saturn (1981), Uranus (1986), and Neptune (1989).
Launched August 20,1977, Voyager 2 has been travelling for more than 36 years and is nearly 12 billion miles from Earth. If we could suddenly travel at the speed of light, we could catch Voyager 2 in just over 14.5 minutes!
The First Quarter Moon, ruddy Mars, and brilliant blue-white Spica form a tight trio in the early nighttime sky. Northern hemisphere observers will see the halfway lit Moon and Mars less than 1 degree apart. Those observers in Central and South America will witness the moon pass directly in front of (occult) Mars!
Go outside just after dark and find the moon… easy. Mars will be just to the right and Spica off to the left. Enjoy.
#OTD in 1997, NASA’s Pathfinder probe, carrying the Carl Sagan Memorial Station and Sojourner rover, lands in the Ares Vallis region of Mars. The landing was anything but gentle… during entry, a parachute was used to slow the descent, and once near the surface, air bags were deployed and the probe dropped, bouncing several times before coming to rest.
The mission exceeded all expectations… more than 17,000 images were returned, chemical analyses was conducted on rocks and soils, and extensive weather data was received. And both the station and the rover outlived their expected design lives.
Pathfinder Atmospheric Descent and Landing
Mars Pathfinder Team Recalls July 4, 1997
#OTD in 1868, astronomer George Ellery Hale is born in Chicago, Illinois. Among his many accomplishments, Hale is probably best known for his work in solar research, and was the architect of several large telescopes.
Few astronomers match Hale’s legacy… founder and long-time editor of the Astrophysical Journal; foreign secretary of the National Academy of Sciences (1910-1921); founder of the National Research Council; author of more than 450 titles (most on the analysis of various scientific research); recipient of several prominent awards; founder and director of the Yerkes Observatory in Williams Bay, Wisconsin (1892-1904) and the Mount Wilson Observatory near Pasadena, California (1904-1923); and inventor of the spectroheliograph, a photographic instrument capable of capturing an image of the sun at a single wavelength.
The minor planet 1024 Hale, the lunar crater Hale, the martian crater Hale, the Hale solar sector boundary, and the colossal 200-inch Hale telescope all bear his name.
Hale died in February 21, 1938 in Pasadena, California.
#TBT Celestron Comet Catcher ad circa 1980.
Breakfast and a show! Make some time tomorrow morning just before dawn; it’ll be worth it. Head outside and look east and you’ll see a very thin crescent Moon next to brilliant Venus. Enjoy.