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Top 10 astronomical events of 2017

Last update 28th December 2017, by Stephanie Warren

It’s been quite a busy year in terms of astronomical events, with major discoveries and fond farewells. This top 10 of 2017 wasn’t easy to organize as each event was equally special and interesting in it’s own way. So here’s my take on the major ones (feel free to contact me if you would have liked to see something else in this selection):

1. Goodbye Cassini: after 20 years in space and 13 years orbiting Saturn, Cassini took the plunge into Saturn to a crushing death. Over its twice extended mission Cassini had sent back amazing pictures of Saturn’s moons and Saturn itself. During its final dive it kept sending more data that will eventually give us an insight into Saturn’s gravity and magnetic field. Loss of contact happened on September 15, 2017 at 7:55:46 a.m. EDT.

2. Coast to coast American solar eclipse: on August 21, 2017 a solar eclipse was visible throughout the US, and was viewed by millions of people. In fact it was the most-viewed eclipse in recorded history, with people flying to the USA from all over the world. This eclipse was also quite unique as there hadn’t been one like this, going from coast to coast, in 99 years.

3. Voyager 1 thrusters fired up after 37 years: scientists fired Voyager 1 thrusters after 37 years not having been used. This required quite a bit of power from the small craft, but it was needed to make sure it was pointing in the right direction in order to keep sending us data from interstellar space. It was unknown whether the thrusters would work or not, but everything went to plan. It’s a tribute to how well it was built.

4. Alien visitor – Oumuamua: this is the first interstellar object detected in our Solar System. It was also at the center of a fiery debate as to whether it’s artificial (alien-made) or natural; the argument was settled … it’s a rock. It was first detected in October, and retracing its trajectory scientists were able to confirm that it was heading out of our system after having come from interstellar space. It’s still under observation as it’s moving away from us.

5. Voyager 1 & 2 – 40 years in space: both spacecraft were launched in 1977 within weeks of each other, but took different paths to explore our Solar System. They were built to last five years, and having exceeded their initial expected lifespan their missions have now been extended three times. This year we celebrated 40 years in space of those amazing travelers. They have still a few years left in them but eventually their power supply will die, and then they will drift in space carrying with them messages from Earth.

6. Last man to walk on the Moon dies: on January 16, 2017 Eugene Cernan died at the age of 82. His last Moon walk occurred in December 1972 during the Apollo 17 mission. It was the mission that returned the largest amount of lunar samples, had the longest lunar extravehicular activities, and established a few other records for human space flight. After ending his career with NASA he became, among other things, a TV commentator for the early shuttle flights.

7. Light source of gravitational waves: on August 17 LIGO detected gravitational waves coming from the merger to two neutron stars in the galaxy NGC 4993. This merger had been theorized but not observed before. Not long after there was a burst of gamma rays which was picked up by NASA’s Fermi Gamma-ray Space Telescope and the European INTEGRAL satellite. Astronomers round the world where then alerted by both the Fermi and LIGO teams about the possibility of an afterglow. Telescopes were then pointed towards the event and the merger was observed across the electromagnetic spectrum. This is in fact the first time an astronomical cataclysmic event has been observed so thoroughly and extensively.

8. Solar System’s twin: this is one of the most interesting astronomical news to come out a the end of 2017. On December 14 NASA announced the discovery of an eighth planet orbiting a Sun-like star called Kepler-90. What made this announcement so extraordinary? This alien solar system resembles our own but on a smaller scale. This mean that our Solar System is not unique, but in fact there could be thousands or millions such systems in the Universe. This discovery was made with the help of the Google AI research team who created and trained a neural network to help analyse the huge data set received from NASA’s Kepler Space Telescope. What is more interesting? The discovery of a system similar to ours or the use of AI to advance scientific discoveries?

9. Sputnik 60 year anniversary: on October 4, 1957 Sputnik 1 was launched, and started the space race between Russian and the USA. It was the first artificial Earth satellite, and it burned up on reentry three months later on October 26, 2017. In that short period of time it had covered a distance of 70 million km (43 million mi) while completing 1440 orbits of the Earth. Not bad for a 58 cm in diameter metal satellite.

10. Water is the trouble: a new study published in July has suggested that there might be more water on the Moon than we had initially thought. The volcanic rocks of the Moon may contain water which could be extracted and used by Moon settlers. This is great news! Mars however has been the center of rather disappointing news; it may not have had flowing water after all … or not as much as speculated. In a study published in November, scientists have analyzed streaks down slopes initially thought to be the result of flowing water. They are now thinking that these streaks may have been caused by dry flows of sand and dust.

Now let's see what happens in 2018! Take a look at our calendar for an idea of what's to come.

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