Another year has passed, and once again we are on the threshold of Christmas.
What astronomical presents did Santa bring us in 2015?
Actually so many new discoveries and innovations have come during the year that it is hard to decide what to mention. There is room here for just a few. The most dramatic must be our first close-up view of Pluto. The things still being revealed to us by the New Horizons spacecraft show a world unlike anything we could have expected. Then there is our first really close look at a comet. The Rosetta spacecraft actually arrived at its target comet in November, 2014, but the discoveries have been steadily flowing out during this year. However, the most astounding thing that has been growing over the last few years, but burgeoned even more quickly in 2015 has been something more subtle: something marking what we could call the maturing of astronomy as a science.
Unlike other sciences, astronomy has for most of its history been restricted to looking at things from afar, and in many ways still is. However, thanks to increasingly sensitive instruments and improved means of processing data, we are now starting to see the cosmos in similar detail to how we see our own world. We are increasingly able to duplicate many cosmic processes in the laboratory or with particle accelerators. Radio telescopes can show us the composition of the dark dust and gas clouds in space and the chemical reactions taking place in them. Sciences which were originally focussed exclusively on the Earth, such as meteorology, climatology, geology, and even oceanography and biology are now being applied to other planets and their satellites. In addition, we now know that most stars have planets and some of those planets are similar to ours. Some scientists have suggested that since there must be many Earth-like planets out there, yet our skies are not filled with the spaceships of alien visitors, we are probably alone in the universe. The rest of us question that conclusion. It does not sound reasonable to assume the rest of the universe is lifeless, and just there for astronomers to study.
Although not exactly a Christmas present, one of the most exciting things to happen here at our observatory over the last year is the construction of the biggest single-antenna radio telescope in Canada and possibly in the world. It consists of four huge metal trough antennas lying on the ground and facing upwards. It is the main part of a project called CHIME — the Canadian Hydrogen Intensity Mapping Experiment. This project is a partnership between Canadian universities and the National Research Council and is intended to map the beginnings of structure in the early universe. Our ability to put CHIME here, along with radio experiments from other organizations, and of course operate our own radio telescopes is due to our electronically quiet site. Almost all manmade signals, including the interference we as a civilization seem to like making, are immensely stronger than the cosmic radio emissions we study. The fact that we have so far managed to maintain this quiet environment in a world of Wi-Fi, smart phones and all sorts of new electronic devices is due to hard work at the observatory and support by local municipalities and Government Regulators, and of course our understanding neighbours. They constitute the hundreds or thousands of Santas who have given us the best Christmas present of the lot ñ our ability to study the universe from our location in the Okanagan.
At 8:48 p.m. PST on Dec. 21 the Sun reached the most southerly point in its yearly travels — the winter solstice. In the predawn southeastern sky we have four planets: Venus, shining like a searchlight, with Saturn below, fainter and hard to see in the glow. Above Venus is Mars, also faint. Further up, more or less in line with the other planets, lies Jupiter, also very bright. The Moon will reach Last Quarter on the 2nd.
Ken Tapping is an astronomer with the National Research Council’s Dominion Radio Astrophysical Observatory, Penticton.