This year was a busy and somewhat self-centred one on Earth.

We were forced to deal head-on with one existential threat (the coronavirus) while waking up to the reality that climate change and the consequences of global warming have moved beyond the confines of talk-back radio debate and into the technical realm known as sh*t-got-real.

Meanwhile, astronomers were no doubt happily distracted by a string of marvels discovered elsewhere in the universe.

January: Rare Earth-sized planet in habitable zone

Maybe the universe was trying to tell us something, but in the same week that news began leaking of a deadly new virus coming out of China, NASA’s Transiting Exoplanet Survey Satellite (TESS) discovered its first Earth-size planet in its star’s habitable zone.

The planet orbits a cool M dwarf star called ‘TOI 700’, found about 100 light-years away in the southern constellation Dorado.

The star has three known planets in its system, the potentially people-friendly one (called ‘TOI 700 d’) sits furthest out, orbiting every 37 days (more birthdays, more often!) and receives from its star 86 per cent of the energy that the Sun provides to Earth.

Conditions may be just right to allow the presence of liquid water on the surface.

February: Another Big Bang, this one a mystery

Astronomers studying a distant galaxy cluster discovered the biggest explosion in history, at least since the Big Bang that got the universe started. This recent bang was so big that astronomers were initially sceptical that it was possible. That is, they couldn’t believe what they were seeing.

This extremely powerful eruption occurred in the Ophiuchus galaxy cluster, which is located about 390 million light-years from Earth. Galaxy clusters are the largest structures in the Universe held together by gravity, containing thousands of individual galaxies, dark matter, and hot gas. Image: X-ray: NASA/CXC/Naval Research Lab/Giacintucci, S.; XMM:ESA/XMM; Radio: NCRA/TIFR/GMRTN; Infrared: 2MASS/UMass/IPAC-Caltech/NASA/NSF

According to a statement from the International Centre for Radio Astronomy Research (a joint venture between Curtin University and The University of Western Australia) the blast came from a super-massive black hole at the centre of a galaxy hundreds of millions of light-years away.

It released five times more energy than the previous record holder.

Professor Melanie Johnston-Hollitt, from the Curtin University node of the International Centre for Radio Astronomy Research, in a prepared statement said the event was extraordinarily energetic.

“We’ve seen outbursts in the centres of galaxies before but this one is really, really massive,” she said. “And we don’t know why it’s so big.”

Professor Johnston-Hollitt said the explosion “happened very slowly – like an explosion in slow motion that took place over hundreds of millions of years.”

The explosion occurred in the Ophiuchus galaxy cluster, about 390 million light-years from Earth.

It was so powerful it punched a cavity in the cluster plasma – the super-hot gas surrounding the black hole.

March: More than 300 new planets found in the neighbourhood

Using data from the Dark Energy Survey, researchers whittled down seven billion dots to find and catalog 316 minor planets located in the far reaches of the solar system.

These little planets, some only 100 kilometres across, are known as trans-Neptunian objects (TNOs), because they exist beyond the orbit of Neptune.

It’s understood there are at least 3000 TNOs in our solar system, including the Kuiper Belt and, most famously, Pluto, which was demoted from full planet status to dwarf planet in 2006 .

April: Did a Death Star take out a planet for real? 

If not a Death Star, something caused a planet known as ‘Fomalhaut b’ to break up into dust and vanish.

Only 25 light years from Earth, ‘Fomalhaut b’ was first photographed by Hubble in 2004 and was revealed as a moving dot. It was formally declared a large planet in 2008.

Then it just vanished.

In April, researchers at the University of Arizona published a paper that suggests ‘Fomalhaut b’ wasn’t a planet in the first place – and was instead a massive cloud of dust caused by a rare collision between two asteroids.

NASA says that by now the debris cloud, consisting of “dust particles around one micron (one-50th the diameter of a human hair) is below Hubble’s detection limit. The dust cloud is estimated to have expanded by now to a size larger than the orbit of Earth around our Sun”.

Whatever the case, planet or cloud, the object’s star Fomalhaut, known as the Lonely Star, is one of the brightest in the night sky. Now it’s lonelier than ever.

May: Comet discovered by amateur does a fly-by 

The newly discovered Comet SWAN made its closest visit to approach to Earth on May 13, at a distance of about 85 million kilometres.

The comet was faintly visible to the unaided eye in the Southern Hemisphere just before sunrise – providing sky-watchers with a relatively rare glimpse of a comet bright enough to be seen without a telescope.

The new comet was first spotted weeks earlier by an amateur astronomer named Michael Mattiazzo using data from the Solar and Heliospheric Observatory (SOHO).

The name SWAN is taken from a SOHO instrument called the Solar Wind Anisotropies, which provided the data.

Comet SWAN is one of nearly 4000 comets discovered using SOHO data from SOHO.

June: Beautiful pictures to lift the Earth’s mood 

Halfway through the stressful year of COVID-19, NASA released some uplifting new images from the Hubble Telescope, including that of galaxy much like our own Milky Way – the barred spiral galaxy NGC 2608, pictured below. See all those glittery stars? Almost every one of them is a galaxy:

Greetings from the barred spiral galaxy NGC 2608 . It’s described as a stretched, but smaller version of our Milky Way. Photo: Hubble Space Telescope

Published on June 18 was this gorgeous image of what’s formally known as NGC 6302 – or more obviously, the Butterfly Nebula. Pretty as it is, the central exploded star of the Butterfly Nebula is about 250,000 degrees Celsius. It’s about 1900 years old, born of massive explosion, and between 2500 and 3800 light-years away, in the constellation Scorpius

It’s what’s known as a planetary nebula, created when a star blows off its outer layers after it has run out of fuel to burn. These outer layers of gas expand into space, forming a nebula which is often the shape of a ring or bubble. In this instance, we get a butterfly:

One of the most beautiful cosmic explosions, the Butterfly Nebula. With a wingspan of more than three light years, it would need a big garden to get about in. Image: NASA, ESA

July: Volcanoes discovered bubbling away on Venus

A new study identified 37 recently active volcanic structures on Venus,  providing “some of the best evidence yet that Venus is still a geologically active planet.”

This 3D rendition shows two coronae on the surface of Venus. They form when plumes of hot material deep inside the planet rise through the mantle layer and crust. The black line indicates missing data. perhaps stolen by Venusians. Image: UMD

According to a statement from geologists at the University of Maryland (UMD) and the Institute of Geophysics at ETH Zurich, Switzerland:

• Scientists have known for some time that Venus has a younger surface than planets like Mars and Mercury, which have cold interiors.
• Evidence of a warm interior and geologic activity dots the surface of the planet in the form of ring-like structures known as coronae, which form when plumes of hot material deep inside the planet rise through the mantle layer and crust.
• This is similar to the way mantle plumes formed the volcanic Hawaiian Islands.

August: Asteroid the size of an SUV, closest fly-by on record

On August 15, if the hair on the back of your neck stood up, it was probably caused by the freaky passing-by of an asteroid, the closest on record. It passed 2950 kilometres above the southern Indian Ocean on Sunday, 3:08 pm Australian Eastern Standard Time.

At roughly three to six metres across, asteroid 2020 QG “is very small by asteroid standards,” according to a statement from NASA.

If it had actually been on an impact trajectory, “it would likely have become a fireball as it broke up in Earth’s atmosphere, which happens several times a year.”

By some estimates, there are hundreds of millions of small asteroids the size of 2020 QG, “but they are extremely hard to discover until they get very close to Earth.”

The vast majority of NEAs pass by safely at much greater distances,  usually much farther away than the Moon.

September: Time travel shown to be theoretically possible 

Wouldn’t it be great to visit the Butterfly Nebula or the side of the universe? You just need a time machine and a set of instructions in order to avoid unintended consequences.

Well, paradox-free time travel is theoretically possible, according to the mathematical modelling of Germain Tobar, University of Queensland Bachelor of Advanced Science (Honours) student.

One of the arguments against time travel is it causes confounding consequences: fiddling with the past or the future, just by turning up. This would lead to paradoxes that make the whole thing unworkable.

The short version, according to Mr Tobar’s calculations, made under the supervision of UQ physicist Dr Fabio Costa, circumstances would adjust around you, no matter what kind of world-altering mission you set yourself.

The immediate consequences of Mr Tobar’s discovery: All those Hollywood films that show everything going to hell when you get a time machine involved… well, they need to find a new set of complications for dramatic effect.

October: People have a future after all 

As we fret about life on Earth not surviving climate change or some rampant bug, researchers have found that we’re probably not living on the best planet in the universe, as we’ve tended to think.

That’s right! We’re not living on prime cosmic real estate after all.

Research led by Washington State University has identified “two dozen planets outside our solar system that may have conditions more suitable for life than our own.”

Some of these planets orbit stars “that may be better than even our sun” – better in that they are slower to change and have longer lifespans.

Geobiologist Dirk Schulze-Makuch, in the journal Astrobiology, describes potential “superhabitable” planets that are older, a little larger, slightly warmer and possibly wetter than Earth.

All the 24 top contenders are more than 100 light years away – so we’ll need that time machine as soon as possible.

November: Early moon rocket returns to orbit the Earth  

Earth has captured a tiny object from its orbit around the Sun and will keep it as a temporary satellite for a few months before it escapes back to a solar orbit.

Initially thought to be a possible asteroid, NASA says it’s probably the Centaur upper stage rocket booster that helped lift the ill-fated Surveyor 2 spacecraft toward the Moon in 1966.

A Centaur upper-stage rocket  of the sort used in the ill-fated unmanned Surveyor 2 moon mission of 1966. Photo: NASA

According to a statement from NASA:

• The Surveyor 2 lunar lander was launched toward the Moon on Sept. 20, 1966, on an Atlas-Centaur rocket. The mission was designed to reconnoiter the lunar surface ahead of the Apollo missions that led to the first crewed lunar landing in 1969.
• Shortly after lift-off, Surveyor 2 separated from its Centaur upper-stage booster as intended. But control of the spacecraft was lost a day later when one of its thrusters failed to ignite, throwing it into a spin.
• The spacecraft crashed into the Moon just southeast of Copernicus crater on Sept. 23, 1966.
• The spent Centaur upper-stage rocket, meanwhile, sailed past the Moon and disappeared into an unknown orbit about the Sun.

Now, in 2020, the Centaur appears to have returned to Earth for a brief visit. On Nov. 8, the object now named 2020 SO slowly drifted into Earth’s sphere of gravitational dominance, a region called the Hill Sphere that extends roughly 1.5 million kilometres from our planet.

That’s where 2020 SO will remain for about four months before it escapes back into a new orbit around the Sun in March 2021.

December: Not the Christmas star, but it’ll do the job

Just after sunset on the evening of December 21, Jupiter and Saturn will appear closer together in Earth’s night sky than they have been since the Middle Ages, according to astronomers from Rice University.

“Alignments between these two planets are rather rare, occurring once every 20 years or so, but this conjunction is exceptionally rare because of how close the planets will appear to one another,” said Rice University phyicist and and astronomer Professor Patrick Hartigan.

“You’d have to go all the way back to just before dawn on March 4, 1226, to see a closer alignment between these objects visible in the night sky.”

Jupiter and Saturn appear to be moving closer together in a conjunction that hasn’t been seen since the Middle Ages. At time of publication, they are about a finger-width apart.  Photo: Getty

Jupiter and Saturn have been approaching one another in Earth’s sky since the summer. From Dec. 16 to 25 (Christmas Day!) the two will be separated by less than the diameter of a full moon.

“On the evening of closest approach on Dec 21 they will look like a double planet, separated by only 1/5th the diameter of the full moon,” said Professor Hartigan in a prepared statement.

“For most telescope viewers, each planet and several of their largest moons will be visible in the same field of view that evening.”

Though the best viewing conditions will be near the equator, the event will be observable anywhere on Earth, weather-permitting, appearing low in the western sky for about an hour after sunset each evening.