How It Works

The Milky Way smells of rum and tastes like raspberries

Our galaxy is truly an amazing place and as scientists, physicists and astronomers develop even more sophisticated methods of exploring it so we discover even more weird and wonderful things about it. Here’s five of the strangest space-facts we could find, kicking off with…

1. The Milky Way smells of rum and tastes like raspberries

This unlikely discovery was made by astronomers studying interstellar objects for new molecules. They had the IRAM radio telescope trained on Sagittarius B2 – a gas cloud at the centre of the Milky Way galaxy – when they found a chemical called ethyl formate. This is one of the aroma compounds that creates the sweet scents of fruit, wine and flowers, and it smells a lot like rum. It is also the chemical that gives raspberries their distinctive flavour.
Ethyl formate is made from ethanol – a common molecule found in star-forming gas clouds – with formic acid, which is a mix of hydrogen, oxygen and carbon atoms. It’s visible to radio telescopes because ethyl formate molecules absorb the radiation from the stars and re-radiate it at radio wavelengths. Ethyl formate molecules are some of the largest molecules ever found in space and are among the building blocks of amino acids, which are vital for life as we know it.
Even though Sagittarius B2 is extremely dense as far as star-forming regions go, it still only has around 3,000 molecules per cubic centimetre, compared to around 25 million trillion molecules per cubic centimetre in the air that we breathe on Earth. So, even if you could breath in the nebula, it would sadly be too rarefied to actually smell the rum or taste the raspberries.

Ethyl formate is made from ethanol – a common molecule found in star-forming gas clouds – with formic acid. It is also the chemical that gives raspberries their distinctive flavour.

2. The Moon is shrinking!

Our Moon didn’t have an easy start in life. It was likely formed in the furnace of a massive collision between Earth and a protoplanet, and has since suffered a multitude of asteroid strikes. These impacts, together with the decay of radioactive elements on the Moon, generated heat. Over millions of years our lunar companion has cooled and, as a result, shrunk. Like an apple that goes bad, its surface has wrinkled, folded and broken. NASA’s Lunar Reconnaissance Orbiter has imaged giant cliffs on the lunar surface called lobate scarps, which formed when the Moon’s interior contracted as it cooled and the surface, like loose skin, wrinkled. Based on the size of the biggest scarps, which formed sometime in the last billion years, the Moon’s radius has shrunk by about 91 metres (300 feet).

Giant cliffs on the Moon’s surface indicate that our natural satellite has shrunk by some 300 feet!

 

3. The Voyager probe carries messages for aliens

The Voyager spacecraft – launched in 1977 and still going strong – are headed into deep space now that they have completed their tour of the planets. On the off-chance that they may be found by aliens, or even humans in the future, each Voyager spacecraft carries onboard a golden phonographic record, devised by famous astronomer Carl Sagan. The record plays natural sounds, music, images and greetings from Earth in 55 languages, while its cover contains technical information describing the world that the Voyager spacecraft have come from, and how to play the messages for any aliens who are unfamiliar with record players.

Launched in 1977, the Voyager probe has now left the Solar System and is carrying its message into deep space

4. A teaspoon of neutron star weighs as much as all the humans in the world

Everything about neutron stars is extreme. They pack up to twice the mass of the Sun into their tiny volumes and are incredibly magnetic. The most magnetic are called magnetars and if one were in orbit around Earth like the Moon, its magnetic field would be able to wipe every credit card on the planet. Stand on their surface and you would feel gravity 200 billion times stronger than on Earth. If the neutron star is spinning, it will fire beams of energy from its rotational axis as particles are accelerated near its magnetic poles – if we are in the line of sight of these rotating beams, we see them pulse as a pulsar.
Neutron stars are created when giant stars die in supernovas. Fusion ceases and the star collapses in on itself, compressing the core. A shock wave rebounds off the core and obliterates the star in a supernova, leaving behind the squashed core that has become so dense that it is only 11.3 kilometres (seven miles) across and electron and proton particles have been compressed together to create an object made entirely of neutron particles. A teaspoon of this would weigh ten billion tons.

Magnetars are young neutron stars with extremely strong magnetic fields

 

5. The Sun could fit 1.3 million Earths inside it

In the sky the Sun doesn’t seem that big. It’s half a degree across, about the same size as the Moon. However, the Moon is much closer, on average around 400,000 kilometres (249,000 miles) away, while the Sun is around 150 million kilometres (93 million miles) away, so to appear the same size as the Moon it must be huge, and it is. The Sun’s diameter is 1.4 million kilometres (870,000 miles), compared to Earth’s tiny 12,742 kilometres (7,918 miles) and even Jupiter’s 140,000 kilometres (87,000 miles). The Sun isn’t even among the biggest stars. One of the largest known stars is called UY Scuti and is 2.4 billion kilometres (1.5 billion miles) across – replace our Sun with this monster star and it would stretch almost all the way out to Saturn.

The Sun’s diameter is 1.4 million kilometres (870,000 miles)

 

This article first appeared in How It Works issue 79, written by Gemma Lavender

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