Our planet is set to gain a second, ‘mini-moon’ tonight (29 September), which will stick around for a couple of months.

The space rock is part of the Arjuna asteroid belt, which is not too far from Earth by space terms, just 2.8 million miles (4.5 million kilometres) away.

It’s called 2024 PT5 and it helps to make up the population of asteroids and comets that are monitored by some of the finest minds in astronomy, at the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS).

The asteroid will not complete a full orbit around Earth though, despite getting caught in its orbit and being given the title of a ‘mini-moon’.

The ‘mini-moon’ will look nothing like this (Getty Stock Image)

What is a ‘mini-moon’?

It can be defined as a ‘temporarily captured object’, as the modestly sized 2024 PT5, with a diameter of roughly 11 metres (the same as a London bus), will stay in orbit for a couple of months before making its way through our Solar System.

The asteroid will orbit our blue planet in a horseshoe-shape, starting on 29 September and going until 25 November.

After escaping from our world’s orbit, it will return to a heliocentric orbit, which is around the Sun – like what we do.

However, it’s predicted that the space rock will not come into Earth’s orbit again until 2055.

How can I see the mini-moon?

Sadly, if you’re not a professional, chances are you won’t be able to see it for yourself.

The event can’t be seen by the naked eye, binoculars or with a consumer-grade telescope, as the mini-moon will have a magnitude of 22 (incredibly low on the -10 to +20 scale), meaning it will be too faint to see.

You’ll need high-tech equipment but even then, some observatories have revealed to The Sun that professional telescope will also struggle to detect 2024 PT5.

2024 PT5 will orbit Earth for about two months (Getty Stock Image)

Who discovered the new mini-moon?

First discovered by the ATLAS telescope on 7 August in South Africa, the Arjuna rock is known as a near-Earth asteroid (NEA).

Arjuna asteroids orbit the Sun on an orbital path that stretches out a bit further into the Solar System compared to our planet’s path, though some may come close to the Earth-Moon system.

Have there been other mini-moons?

The short answer is yes.

In our time observing space, 2024 PT5 has not been the first mini-moon collected by out planet, as it is known to capture and pull NEAs into its orbit.

Back in February 2020, a tiny asteroid named 2020 CD3 was found to have been orbiting Earth for a few years, before leaving our orbit the following month.

In 2016, there was an object called 2016 HO3, which was 40-100 metres in diameter, though it did not orbit the Earth so it was not a moon – but it oddly moved in sync, looking like it was orbiting our planet but it was really orbiting the Sun.

Sorry I know we’re one day away from Friday, but I thought I’d just let you know that an asteroid the size of the Empire State Building could hit the earth in just over 150 years.

NASA discovered the rare B-type asteroid back in 1999 and has dubbed it as one of the ‘most dangerous’ objects in the solar system.

The 1,614-foot-wide (492 meters) asteroid is big enough to cause significant destruction on Earth, and is capable of digging itself several miles down into the planet’s surface.

This would most likely cause an earthquake spanning hundreds of miles of area from the impact location.

Thankfully, there are two important pieces of info here:

1) You’ll be dead if/when it happens

2) There’s a 1 in 2,700 chance of it actually happening

NASA

But if it does head to us, you best sure that NASA has over 150 years to get prepared for the rock – titled asteroid Bennu – with 24 September 2182 being the most likely due date.

While the chances of a strike have risen over the next century or two, NASA’s improved probabilities come courtesy of its OSIRIS-REX spacecraft, which has been on a five-year mission to study Bennu up close and collect rock samples for scientists to study back home.

And after a length journey, NASA announced in December that a grain from the asteroid Bennu would be brought to Diamond Light Source, the UK’s national synchrotron, for scientific measurements.

The grain is from the 100 milligrams of sample sent to the Natural History Museum (NHM) in London, small fraction of the approximately 70 grams of Bennu rock.

This will not only provide new scientific data and new knowledge about the asteroid, but the origins of our solar system.

Pexels

Dr Ashley King, a planetary scientist from the Natural History Museum, said: “Although this sample is small, only a little larger than a grain of sand, it is more than enough to reveal a lot of information about our solar system.

“Diamond is key as it enables non-destructive testing of the samples, which is vital.

“The Bennu samples will be used to test theories that suggest asteroids like Bennu may have been involved in delivering key components to the young Earth system some 4.5 billion years ago.

“Potentially, it’s how we got the water in our oceans and some of the compounds that were necessary to kick-start life.

“Our experiments are focussed on understanding the mineralogy, composition and textures of the samples to be able to tell the story of Bennu’s history.

“Using DIAD (Dual Imaging And Diffraction) we’ll be able to explore the mineralogy of Bennu in 3D.”

The astronomer who unveiled the ‘Pale Blue Dot’ in the 1990s has explained why he believed the image was so important for all of mankind to see.

Throughout his life, legendary planetary scientist Carl Sagan dedicated his work to furthering our understanding of space and the possibility of extraterrestrial life (aka aliens) existing.

Often described as ‘the scientist who made the Universe clearer to the ordinary person’, Sagan took the complex – and often mind-boggling – world of astrophysics and made it easily accessible to the likes of you and I.

In 1990, Sagan unveiled an image called the ‘Pale Blue Dot’ to the world, take a look at the image below:

The image was released in 14 February 1990 (NASA/JPL-Caltech)

Now, upon first glance I know this photo looks like an image of the night sky taken in your back garden on an old mobile phone.

However, I assure you this is not an average photo of the night sky, but instead an image captured by by NASA’s Voyager 1 around 3.7 billion miles (6 billion kilometers) from the Sun.

The subject of this photo? Planet Earth.

Look closely at the photo and you’ll notice a small pale blue dot just off centre in the upper right part of the image, that’s us.

After seeing the images, Sagan was inspired to use it as a way to drive home just how unique our situation is in the universe.

Talking about the lack of interstellar life in a press conference for the image, Sagan said: “For me, that underscores the rarity and preciousness of the Earth and the life upon it.

“On that blue dot, that’s where everyone you know. Everyone you ever heard of, and every human being who ever lived, lived out their lives.”

Urging others to use the image as inspiration to look after our collective home, he continued: “Just speaking for myself, I think this perspective underscores our responsibility to preserve and cherish that blue dot, the only home we have.”

I can think of a few people who could use such a reminder, that’s for sure.

That’s us, the blue dot (YouTube/The Planetary Society)

Like the astronauts who’ve spoken candidly about the impact of the ‘Overview Effect‘, the image leave a lasting impact on Sagan. He would later go on to name his 1994 book Pale Blue Dot: A Vision of the Human Future in Space after the image.

Proving this photo is definitely not your typical image of the night sky.

The legacy of the ‘Pale Blue Dot’ has gone on to inspire more than Sagan in the subsequent years as well, with Garry Hunt telling the BBC in 2020 that he often uses the image as a way to drive home the importance of taking climate change seriously.

“Every time I give a climate talk and I talk about what you’re doing now to make a change – I show this picture because it shows the Earth is an isolated speck. This tiny blue dot is the only place we can possible live, and we’re making a jolly good mess of it,” he said in the interview.