Just in case Doctor Who ever needs a new opening credits sequence, NASA has provided a stunning new look at a comet currently flying close to Earth. Specifically, Comet A3, which is currently streaking across our Solar System at 80.47km per second after surviving its close encounter with the Sun last month.
The comet was snapped by the NASA Solar and Heliospheric Observatory (SOHO) spacecraft. The image (see above) shows the comet on the right side as a white streak of light, opposite the planet Mercury, which is the bright white spot on the left.
The big blue circle in the image’s centre is the Sun, whose glare has been blocked using an instrument known as a coronagraph.
It's believed the comet originated from the Oort Cloud, also known as the Öpik–Oort Cloud. This region forms the outer ‘shell’ of our Solar System and contains potentially billions of icy, mountain-sized fragments of debris.
The Oort cloud is so far away from the Sun that it can take comets hundreds of thousands of years to complete an orbit.
Comets are composed of ice and rock, surrounded by gas and dust left over from the formation of the Solar System. They span from a few kilometres to tens of kilometres in width. As they move closer to the Sun and heat up, they develop a tail that is millions of kilometres long.
But why is this comet called Comet A3? The comet’s full moniker C/2023 A3 (Tsuchinshan–ATLAS) pays homage to the Tsuchinshan Observatory which first discovered it, and the South African ATLAS telescope that later identified the comet. The '2023' in the name denotes the year it was discovered, with 'A3' signifying it was first spotted in January.
Why is this comet important?
What makes the comet’s appearance so special is its rarity. It's currently at a point in its 80,000-year orbit that brings it close enough to the Sun for us to see it, a phenomenon that happens with only a small fraction of comets.
The animation below shows the moment this happened.
While NASA captured these incredible images using SOHO, you don't have to be a NASA satellite hurtling through space to spot the comet for yourself...
How to see Comet A3
The comet will re-appear tonight in the early evening during an estimated 30-minute window after the Sun sets. Tomorrow, you may be able to catch a glimpse of it during the day when it travels to its closest point to Earth, which is still a humble 70 million kilometres away.
You’ll have your best chance of seeing Comet A3 if you travel to an area with less light pollution.
Using a pair of binoculars or a telescope will improve your chance of catching a glimpse of the comet, and will be necessary if you want to try your chance of viewing it later this month.
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