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Galileo's observations
Galileo uses telescope for astronomical observations. Galileo didn't invent the telescope but he was among the first to use a telescope to examine the heavens. He carried out important observations of the Sun, Moon, Planets, and Stars. -
Maunder minimum
During the Maunder minimum almost no spots were seen on the Sun. This was also a time of cold climate in Western Europe and North America. -
Giovanni Cassini
Giovanni Cassini discovers Great Red Spot of Jupiter. Although its size and darkness have changed with time, the Great Red Spot has been continuously present since the time of Cassini's discovery. -
Discovery of Neptune and Uranus
Calculations of Adams and Leverrier lead to discovery of Neptune. Adams and Leverrier independently calculated the location of the unknown planet, Neptune, that was required to explain discrepancies in the orbit of Uranus. -
Kuiper Belt
Gerard Kuiper proposes existence of Kuiper Belt of comets. Kuiper proposed that the comets with periods of less than 200 years originate in a flatted belt of comets whose inner edge lies just beyond the orbit of Neptune. -
Van Allen Radiation Belts
James Van Allen discovers Van Allen radiation belts. Explorer 1, the first satellite launched by the United States, carried a Geiger counter built by Van Allen. The Geiger counter showed that there are zones of trapped energetic ions and electrons beyond Earth's atmosphere. -
Frank Drake's Observations
Frank Drake uses radio telescope to search for interstellar signals. Drake searched at a wavelength of 21 cm for artificial signals from creatures on planets orbiting two nearby stars. No signals were detected. -
Apollo 17
Last Apollo mission to Moon. Apollo 17 concluded the series of lunar landings in which a dozen astronauts explored the Moon. -
Mariner 10
Mariner 10 encounters Mercury. After passing Venus, Mariner 10 encountered Mercury four times, sending back pictures of Mercury's surface. Mariner 10 is the only spacecraft that has flows past Mercury. -
Charon
James Christy discovers Pluto's moon, Charon. Chrisy noticed that Pluto's image had a bump on it. The bump proved to be a satellite, Charon. -
VLA
Very Large Array begins operations. The Very Large Array (VLA) is an array of 27 radio telescopes that work together to produce radio images that are comparable to those of traditional optical telescopes. -
Hubble
Hubble Space Telescope launched. The HST has produced images of breathtaking clarity and has allowed astronomers to see light from more distant objects than ever before. -
Pathfinder
Pathfinder lands on Mars, Mars Global Surveyor begins mapping of Mars. The Pathfinder lander and the Sojourner rover it carried landed in an ancient Martian riverbed. The Mars Global Surveyor is sending back pictures of Mars that have unprecedented clarity and detail. -
Lunar Prospector
Lunar Prospector intentionally crashed into Moon in attempt to identify water. None is found. This shows how desperate people can be when trying to find new discoveries. -
2016
An international team of astronomers, led by Nicolas Martin of the Observatory of Strasbourg in France, has detected a new, very faint stellar system, designated SMASH 1. This compac, very faint system could be a satellite of the Large Magellanic Cloud (LMC). The findings are reported in a paper published Sept. 19 on arXiv.org.