The Backyard Astronomer: The astronomy year in review

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      Looking back on 2021, there were many great space stories in the news, including two lunar eclipses back in May and November.

      By coincidence, two more total lunar eclipses will occur in May and November of 2022.

      We were also entertained by three great meteor showers in January, August, and December, but the bright moon ran major interference.

      Speaking of bright things in the sky, the Northern Lights were prominent last month, particularly in Western Canada, painting the sky green.

      The never-ending list of exoplanets continues to grow, with a total of 4,884 confirmed worlds and another 8,288 candidates. This search continues via ground- and space-based telescopes. So, next time you look up at those twinkling points of light, remember that you are looking at mini solar systems, with at least one planet orbiting its parent star.

      Gary Boyle

      After all, our sun is but one of 300 billion stars in the Milky Way galaxy.

      It was this time last year that the Japanese Hayabusa mission successfully returned soil samples from the asteroid 25143 Itokawa. The sample shows that water and organic matter that originate from the asteroid itself have evolved chemically through time.

      It has long been the thought by astronomers and scientists that the building blocks of organic compounds needed to create life began in the solar system and were delivered to the young Earth via meteorites. Missions such as this have shed new light on this theory. Meteorites and comets contain small amounts of water, and impacts over millions of years have most likely delivered water to the Earth.

      Comparable to the list of exoplanets, 70 more rogue planets have been detected floating through space. These are “outcasts” from their solar systems by some event such as the star exploding, thus launching a planet or planets on a path to nowhere. Or some of them could have been overpowered by the gravity of larger planets and slingshot out of their systems, far away from the light and (possible) warmth of their suns.

      Until now, the sun has been studied by Earth-bound telescopes and orbiting satellites. The amount of information that has been learned is outstanding, but the missing key has always been a physical examination. Never before has a spacecraft touched the sun—until the Parker Solar Probe was launched in 2018.

      Artist's rendition of the Parker Solar Probe approaching the sun.
      Wikimedia Commons/NASA/Johns Hopkins APL/Steve Gribben

      Over the years, the craft made multiple manoeuvres as it got closer to the sun. In December of this year, the probe touched the sun's upper atmosphere, the corona, which is only seen from Earth during a total solar eclipse, when the moon blocks the sun's blinding light.

      Over the next few years, it will skim closer to our star, and by the year 2025 it will be racing along at an unheard-of speed of 690,000 kilometres per hour, or 192 kilometres per second. Its 11.4-centimetre-thick heat shield allows it to operate at about 29°C and not fry the electronics.

      The newest addition to the Martian fleet came with the deployment of the SUV-sized rover Perseverance and the Ingenuity helicopter anchored under it. The two blades of the small helicopter spin in opposite directions to help give lift in the thin Martian atmosphere. To date, it has logged 30 minutes in a series of short flights. This is the first time such a vehicle has been used on the Red Planet.

      The Mars Perseverance rover and its tire tracks on the surface of the Red Planet.
      Wikimedia Commons/NASA/JPL

      Private companies, not just NASA, have proved that they have the right stuff to launch into space. Jeff Bezos and Blue Origin allowed 90-year-old William Shatner and retired NFL player Michael Strahan to touch space by rocketing past the so-called Karman line, 100 kiolometres above the Earth's surface.

      But Elon Musk has taken space travel one step further by transporting astronauts and supplies to the International Space Station via the SpaceX Dragon cargo ship. It is the same Dragon capsule that almost had to be used as an emergency escape vehicle when the International Space Station was subjected to a dangerous debris field from a purposely blown-up satellite. The danger has all but passed, but there were some anxious moments.

      Space is dangerous, with hazardous solar radiation and cosmic rays. As well, more than 23,000 pieces of orbital debris larger than a softball are being tracked, and there are a half-million pieces the size of a marble or larger, with approximately 100 million pieces of debris being about one millimetre and a bit larger. All are moving at 28,000 kilo,metres per hour, or almost eight kilometres per second.

      In September of 2022, the DART (Double Asteroid Redirection Test) mission will arrive at the 800-metre-wide asteroid 65803 Didymos to deflect a small (160 metres wide) moonlet, Dimorphos. This is a test to see if a potentially dangerous asteroid coming toward Earth can be slightly deflected, thus changing its course and missing our planet. This particular asteroid is in no way on a collision course with our home planet.

      Artist's illustration of the DART spacecraft approaching the Didymos biinary system. At the bottom right is the Italian CubeSat LICIACube, which will take pictuers of the craft's test collision with the smaller moonlet.
      NASA/JHUAPL/Steve Gribben

      Finally, the long-awaited James Webb Space Telescope (JWST, successor to the Hubble Space Telescope) was launched on Christmas Day. It has a much larger mirror system than does the venerable Hubble and will study infant galaxies in the near-infrared, thus allowing us to see through the gas and dust of the earliest galaxies.

      The telescope's sun shield is the size of a tennis court and will both shade the telescope from the heat of the sun and block the light of the Earth and moon. It will operate at a distance of 1.5 million kilometres from the Earth, where the temperature of space is -223°C. The JWST will be able to look back to the beginning of the universe, some 13.8 billion years ago.

      One of its many projects will be to see if black holes helped create the galaxies or if they came afterwards. It will also look for signs of life in the atmospheres of distant exoplanets.

      Clear skies.

      Known as “The Backyard Astronomer”, Gary Boyle is an astronomy educator, guest speaker, and monthly columnist for the Royal Astronomical Society of Canada as well as past president of the Ottawa Centre of the RASC. He has been interviewed on more than 50 Canadian radio stations as well as television across Canada and the US. In recognition of his public outreach in astronomy, the International Astronomical Union has honoured him with the naming of Asteroid (22406) Garyboyle. Follow him on Twitter: @astroeducator, Facebook and his website: www.wondersofastronomy.com

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