June 17, 2019 - The Brewer who Discovered Triton
The Brewer who Discovered Triton William Lassell, born 220 years ago this week, made a fortune brewing beer in Liverpool during the mid-19th century. With his sizable profits, Lassell financed his real passion, astronomy. He built a 61 cm (24 in) reflecting telescope, which at the time was the most powerful telescope in England. In September 1846, he read about the discovery of the planet Neptune, and less than a month later he turned his telescope toward Neptune and discovered its largest Moon, Triton, which is slightly smaller than Earth’s Moon. It has one of the coldest surfaces known anywhere in the solar system, and it is one of only a few worlds that possess a nitrogen-rich atmosphere. This composite view, based on Voyager 2 data, shows Neptune as seen from the surface of Triton.
Image credit: NASA / JPL
Weekly Calendar
June 17 - 23, 2019
Holidays - Sky Events - Space History
Monday 17
Full Moon 4:31 AM ET
Venus 5° north of Aldebaran
1985: STS-51G Discovery launched
Tuesday 18
Mercury 0.2° north of Mars
1799: William Lassell born
1983: STS-7 Challenger launched; Sally Ride becomes first American woman in space
2009: Lunar Reconnaissance Orbiter (LRO) and Lunar Crater Observation and Sensing Satellite (LCROSS) launched
Wednesday 19
Saturn 0.4° north of Moon
Pluto 0.07° north of Moon
1999: QuikSCAT launched
Thursday 20
1985: NASA announces cola wars will take place on shuttle mission STS-51F
1996: STS-78 Columbia launched
Friday 21
Mercury 6° south of Pollux
Solstice 11:54 AM ET
1993: STS-57 Endeavour launched
2004: SpaceShipOne launched, first privately-funded human space flight
Saturday 22
Neptune appears stationary
1675: Royal Greenwich Observatory founded
1973: 28-day Skylab 2 mission ends
2000: NASA announces evidence of present-day liquid water on Mars
Sunday 23
Mars 6° south of Pollux
Moon at apogee
Mercury at greatest elongation (25° E)