February 25 2017 Astronomy Newsletter
Here's the latest article from the Astronomy site at BellaOnline.com.
European Astrofest 2017
It was the 25th Astrofest – and how things have changed since the first one! No one knew then if other stars had planets. Pluto was still a planet and its discoverer Clyde Tombaugh was still alive. The Rosetta mission was in the very early planning stages, and Cassini-Huygens hadn't been launched.
*Star with 7 Earth-sized planets*
TRAPPIST-1 is a dwarf star 40 light years away in the constellation Aquarius. All of the planets are closer to the star than Mercury is to the Sun, which may not seem very habitable at first sight. However the star is an ultra-cool dwarf and its habitable zone is much closer to it than the Sun's habitable zone. It's cool enough for liquid water to survive on planets orbiting quite close. The planets are also close to each other. According to NASA, “If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth’s sky.”
(1) February 19, 1986: Mir was launched by the Soviet Union. Mir was the first modular space station and was assembled in orbit. It was first continuously inhabited long-term research station in orbit. The failing station was deorbited in March 2001.
(2) February 20, 1965: NASA's Ranger 8 ended its mission by a crash landing on the Moon. The Ranger program was designed to obtain close-up images of the Moon's surface to help choose landing sites for Apollo missions. Ranger 8 transmitted 7,137 images before its mission was ended.
(3) February 20, 1965: John Glenn became the first American to orbit the Earth. Glenn's space capsule Friendship 7 took him around the Earth three times before its splashdown.
(4) February 23, 1990: Pioneer 11 crossed the orbit of Neptune on its way out of the Solar System. The spacecraft went beyond the most distant planet, but since there are dwarf planets and other objects out there, it didn't leave the Solar System.
(5) February 23, 1987: the light from supernova SN 1987A reached Earth. The supernova occurred in the Tarantula Nebula in our neighboring galaxy the Large Magellanic Cloud. It was the closest supernova seen in nearly four hundred years. Visible to the unaided eye in the southern hemisphere, it has greatly increased our understanding of this spectacular phenomenon. (More on the Tarantula Nebula: http://www.bellaonline.com/articles/art303857.asp
(6) February 24, 1968: the discovery of the first pulsar was announced. A pulsar is a fast-rotating neutron star that emits a beam of electromagnetic radiation. We can only detect it when it's pointing towards us, rather like a lighthouse, so it seems to pulse. A neutron star is the remnant of a massive star following the collapse of its core in a supernova explosion.
(1) February 23, 1945: Svetlana Gerasimenko was born. Gerasimenko was the co-discoverer of comet 67P/Churyumov–Gerasimenko, the comet which was studied by the Rosetta mission. Both the Rosetta spacecraft and the lander Philae are on the comet as it continues its orbit.
(2) February 26, 1842: Camille Flammarion was born. He was a French astronomer and prolific author.
Please visit http://astronomy.bellaonline.com/Site.asp for even more great content about Astronomy. I hope to hear from you sometime soon, either in the forum http://forums.bellaonline.com/ubbthreads.php/forums/323/1/Astronomy or in response to this email message. I welcome your feedback!
Do pass this message along to family and friends who might also be interested. Remember it's free and without obligation. I wish you clear skies.
Mona Evans, Astronomy Editor
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