2020 a noteworthy year in astronomy

It has been interesting how much attention the conjunction of Jupiter and Saturn attracted in the media. Maybe one of the reasons for this is that amidst a year of hardship and tragedy, it is reassuring to see the rhythm of the universe just chugging along, predictably. The two planets will be close together for a while, so there is still time to look at, or even better, point a telescope at those two dots, one bright and one dim, low in the southwest after sunset.

Even in the midst of the COVID-19 pandemic some noteworthy things happened in astronomy during 2020.

First, there is the discovery of phosphine in the atmosphere of Venus.

This is a compound with molecules made up of one phosphorus atom combined with three hydrogen atoms.

Here on Earth, the only naturally occurring phosphine is generated by the rotting of vegetable material in boggy water where there is low oxygen.

It bubbles to the surface of the water, and burns spontaneously in the air, forming flickering marsh lights.

In British folklore these lights are attributed to a malicious fairy, called Will-o-the Wisp, who wants to attract you deeper into the bog, where you could drown.

The surface of Venus is too hot for any of the life processes we know of.

However, temperatures in the upper atmosphere are more comfortable, and there is water and a mixture of different chemicals available to react together.

The fact that we know only one natural process for making phosphine, and that involves living things working on biological material, does not prove there is life in Venus's atmosphere. There could be chemical reactions we have yet to learn about.

However, this discovery has certainly attracted a lot of interest. We certainly know of living things, extremophiles, here on Earth, making their living in near-boiling, acidic water and other hostile places, so the possibility of living things in the atmosphere of Venus does not stretch our imaginations too much.

OK. I’m biased, but I think the astronomical star of 2020 is CHIME, the Canadian Hydrogen Intensity Mapping Experiment. The instrument consists of an array of four huge trough-shaped antennas with a total signal collecting area of 8,000 square metres. The objective of the experiment was to map the structure of the hydrogen clouds in the young universe.

Basically, hydrogen is the starting ingredient for everything in the universe. However, the design of this telescope makes it ideal for a completely different sort of observation.

There are objects far out in space that occasionally emit a short (thousandths of a second) burst of radio emission. These objects are scattered all over the sky, producing a number of these pulses, known as “fast radio bursts” or FRBs, a day.

They were discovered serendipitously when a dish type radio telescope, which sees a very small patch of sky, happened to be looking in the right direction at the right time.

To do its job, CHIME sees almost all the sky overlying the observatory. So if anything happens in the sky above the horizon, CHIME will almost certainly catch it. So far CHIME has captured hundreds of these strange FRBs.

Lying at huge distances, the objects must be emitting a prodigious amount of energy. However, to produce a pulse a millisecond in duration, the object cannot be bigger than about 300 kilometres in diameter. The only known things that might fit the bill are neutron stars or black holes.

Underneath that reassuringly smooth-running cosmos there is another less well-understood universe that is much less predictable.

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Saturn and Jupiter lie very close together low in the southwest just after dark. Mars is high in the southeast. Venus lies low in the dawn glow. The moon will be full on the Tuesday.

I would like to take this opportunity to wish you all a Happy 2021.