2021 Astronomy Year In Review
Looking back to 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 2022. We were also entertained by three great meteor showers in January, August and December, but the moon ran major interference. 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, you are looking at mini solar systems of at least one planet orbiting its parent star. After all, the 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 return soil samples from the asteroid Itokawa. The samples show that water and organic matter which originate from the asteroid itself have evolved chemically through time. It has long been the thought of astronomers and scientists that 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. 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 system, cast away by some event such as the star exploding, thus launching it on a path to nowhere. Or some could have been overpowered by larger planets in their solar system and were slingshot out of it, far away from the light and (possible) warmth of their sun.
Until recently, the sun has been studied by earth-bound telescopes and orbiting satellites. The amount of information learned is outstanding but the missing key was a physical examination. Never before had a spacecraft touched the sun until the Solar Parker Probe launched in 2018. Over the years the craft made multiple manoeuvres as it gets closer to the sun. In December of 2021, the probe touched the upper atmosphere of the sun’s corona, which is only seen from Earth during a total solar eclipse when the moon blocks the blinding light. Over the next few years the probe will skim closer to our star and by the year 2025 is will be racing at an unheard of speed of 690,000 kilometres per hour, or 192 kilometres per second. Its 11.4-centimetre thick heat shield alloys it to operate at about 29 degrees Celsius and not fry the electronics.
The newest addition to the Martian fleet came with the deployment of the SUV-sized rover Perseverance and 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.
Private companies have proved they have the right stuff to launch into space – not just NASA. Jeff Bezos and Blue Origin allowed 90-year-old William Shatner and retired National Football League (NFL) star Michael Strahan to touch space by passing the 100 Karman Line. 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 was almost used as an emergency escape vehicle. The International Space Station was subjected to a dangerous debris field of a purposely blown-up satellite. The danger has all but passed, but there were some anxious moments.
Space is dangerous. Along with solar radiation from the sun and cosmic rays from the cosmos, more than 23,000 pieces of orbital debris larger than a softball are being tracked. Half a million pieces are the size of a marble or larger, with approximately 100 million pieces of debris-about one millimetre and a bit larger. All moving at 28,000 km/hr, or almost 8 km/sec.
In September of 2022, the DART mission will arrive at the 800-metre wide asteroid Didymos to deflect a small 160-metre wide moonlet Dimorphos. This is a test to see if a potential asteroid coming towards earth can be slightly deflected, thus changing course and missing our planet. Fear not – this particular asteroid is only a test subject and is no way on a collision course with our home planet.
The long-awaited James Webb Space Telescope (successor to the Hubble Space Telescope) was launched on Christmas Day. It has a much larger mirror system and will study infant galaxies in the near-infrared, thus allowing us to see through the gas and dust of the earliest galaxies. The sun shield measures the size of a tennis court and will 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 degrees Celsius. The JWST will be capable of looking 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.
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 United States. 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