Category Archives: Astronomy

Did life come from the centre of the galaxy?

Astronomy

Did you know that chemical building blocks for life on Earth might have come from the centre of the Milky Way?

German researchers used 20 x 12 metre dishes at the ALMA radio telescope in Chile to detect radiowaves emitted from Sagittarius B2, a huge star-forming cloud near the centre of our galaxy.

Among the spectra were signature radiowaves for iso-propyl cyanide.

This is the first branched carbon molecule discovered in interstellar space that is similar to organic molecules associated with life on Earth (e.g. amino acids).

Therefore, it is possible that life-giving organic compounds might have been produced in huge gas clouds like Sagittarius B2, then hitched a ride on meteorites/comets to seed life on Earth.

If it happened here, this makes it more likely it also happened elsewhere in the galaxy.

 

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Background

All life on Earth is based on organic compounds containing carbon (e.g. amino acids, DNA, fats, sugars, ATP, etc).

Carbon was chosen by nature because it is abundant (4th in the universe, 15th on Earth, 2nd in humans) and forms up to four bonds per atom with itself (forming chains) and other elements (forming compounds). This flexibility and stability means it can produce an almost infinite number of molecules/compounds.

So where did they come from? And could they have given rise to life elsewhere in the universe?

Several carbon-based organic compounds have previously been detected in space, but they have all been straight-chained carbon molecules.

Carbon compounds associated with life on Earth are usually branched.

Materials and Methods

German researchers used 20 x 12 metre dishes at the Atacama Large Millimetre Array (ALMA) radiotelescope in Chile to detect radiowaves emitted from Sagittarius B2, a huge star-forming cloud near the centre of the Milky Way galaxy. The spectra detected were compared to spectra from control samples on Earth or computer-predicted spectra.

Results

Among the spectra of many molecules from Sagittarius B2 were radiowaves for iso-propyl cyanide.

This is the first branched carbon molecule discovered in interstellar space that is similar to organic molecules associated with life on Earth.

The iso-propyl cyanide forms in or on dust-grain ices at around 55-75 Kelvin (-218° to -198°C), according to their models.

Discussion

Branched organic compounds have also been discovered in meteorites.

Therefore, it is possible that life-giving organic compounds might have been produced in huge gas clouds like Sagittarius B2, then hitched a ride on meteorites to seed life on Earth.

If it happened here, this makes it more likely it also happened elsewhere in the galaxy.

More sensitive telescopes may one day be able to measure amino acids in interstellar space. If so, this further increases the chance that life originated in space (at least the building blocks).

Article

Detection of a branched alkyl molecule in the interstellar medium: iso-propyl cyanide

Belloche et al., 2014 Science 345:1584-7

Keywords

Organic, compound, molecule, carbon, life, star, Earth, galaxy, universe, interstellar, meteorite, branched, amino acid, radiowave, radiotelescope, radio, telescope

Subject

Science, Earth and Space, ST2-9ES, ACSSU048, ST3-8ES, ACSSU078, SC4-12ES, ACSSU115, SC4-14LW, ACSSU111, ACSSU149, SC5-12ES, ACSSU188, SC5-15LW, ACSSU185, SC5-17CW, ACSSU178, ACSSU179

Mysterious alien signals from the kitchen

Astronomy, Physics

Did you know that the mysterious ‘peryton’ signals detected by radio telescopes were accidentally caused by hungry scientists cooking their lunch?

Perytons are short, intense pulses of radio energy (1.4 GHz) that astrophysicists thought came from neutron stars as they collapse to form black holes.

However, Australian PhD student Emily Petroff from Swinburne Institute of Technology in Melbourne, worked out where they really came from.

She was working at the Parkes radio telescope in NSW in 2014 when she noticed that the perytons were detected more frequently at lunchtimes.

It turned out that even though microwave ovens normally operate at 2.3-2.5 GHz, if the door is opened before the timer is complete (without turning it off first), it emits a burst of energy at 1.4 GHz, same as the perytons.

Therefore, Emily discovered that the source of the mysterious perytons was simply impatient scientists grabbing their lunch out of microwaves ovens.

Article

Identifying the source of perytons at the Parkes radio telescope

Petroff et al., 2015 (Apr 9) Mon. Not. R. Astron. Soc. (InPress)

Keywords

Radio, telescope, astronomy, wave, signal, energy, electromagnetic, space, star, black hole, peryton, frequency, hertz, Parkes

Subject

Science, physics, astronomy

Dung beetles have stars in their eyes

Astronomy, Biology, Earth Science

Did you know that dung beetles use the stars as a satnav?

Many dung beetles are nocturnal and roll their balls of dung around at night.

They use the moon for direction.

However, when the moon isn’t out (around half of the nights in a month), how do they know where to go?

This paper put dung beetles inside a planetarium in South Africa and showed them the moon, individual stars and the milky way to see which they used for direction on moon-less nights.

They found that the beetles can use the white band of the milky way to orientate themselves.

This is the first example of any animal using the milky way for orientation.

 

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Background

Many animals use the night sky for orientation/direction at night, especially the moon.

Only birds, seals and humans are known to use stars.

Dung beetles lay eggs in large balls of dung, roll it to a suitable position and bury it. The dung feeds their offspring when they hatch.

Many dung beetles are nocturnal, and they are known to use the moon for direction.

They have relatively primitive compound eyes that can detect the moon, but not individual stars.

So when the moon is not in the sky (~half of all nights), how do they orientate themselves on the other nights?

Materials and Methods

The authors went to South Africa to study the dung beetles.

They recorded the movements and direction of the dung beetles rolling their dung balls using cameras.

They measured the distance and direction of travel when the beetles had a transparent v cardboard helmet on (only the latter blocked) out the night sky.

To distinguish between the effect of the moon and stars, they took the beetles and their dung balls to the Johannesburg planetarium and exposed them to the full night sky, moon, stars, etc.

Results

When the dung beetles couldn’t see the night sky due to the cardboard helmet blocking their vision, their direction was impaired, indicating they used the night sky for orientation.

At the planetarium, it was discovered that beetles could use the moon or the band/streak of the milky way for orientation, although they couldn’t use individual stars.

Discussion

On nights when there is no moon, the dung beetles can use the longitudinal white band of the milky way to orientate themselves while they are rolling around their dung balls.

Their primitive compound eyes don’t allow them to distinguish individual stars, but instead they use the longitudinal white band of the milky way to orientate themselves.

These are the first insects shown to use stars for orientation, and the first use of the milky way for the whole animal kingdom.

Article

Dung beetles us the milky way for orientation

Dacke et al., 2013 Current Biology 23:298-300.

Keywords

Insect, beetle, direction, orientation, environment, moon, stars, milky way, night, sky, dung, planetarium, South Africa, compound, eye

Subject

Science, biology, ST1-8ES, ACSSU019, ST2-11LW, ACSSU073, ST3-11LW, ACSSU094, SC4-15LW, ACSSU112, SC5-14LW, ACSSU176

Russian cosmonauts wee on the wheel of the bus before launch

Astronomy, Physics

The Russian Soyuz rocket is currently the only spacecraft capable of carrying people to the International Space Station.

It uses 274 tonnes of explosive rocket fuel, but surprisingly has a remarkably good safety record.

Perhaps it has something to do with the strange rituals performed by cosmonauts and engineers.

Such as, weeing on the back right-hand tyre of the bus on their way to the launch pad or spinning around in swivel chairs hours before launch to get them used to weightlessness.

Read below for more silly rituals performed by cosmonauts/astronauts at Baikonur Cosmodrome.

 

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When cosmonauts/astronauts arrive at Baikonur Cosmodrome, their plane is always welcomed by cheerleaders wearing coats, hats, gloves and gold-coloured pom-poms.

All cosmonauts/astronauts plant a tree in the Avenue of Trees at Baikonur Cosmodrome and watch a cult Russian Western movie called “The White Sun of the Desert”.

As the massive rocket is slowly dragged to the launch pad by a diesel locomotive, spectators place coins on the rail track to be flattened for good luck.

Cosmonauts/astronauts sign their names on the door of their bedroom at Baikonur Cosmodrome, a wall in the museum at Baikonur and on the charred outer casing of their space capsule on return.

To acclimatise cosmonauts/astronauts to weightlessness and reduce space sickness, they are spun around on a swivel chair a few hours before take-off.

On the way to the launch pad, all male cosmonauts/astronauts must get out of the bus and wee on the back right-hand tyre. A tradition started by the first cosmonaut, Yuri Gagarin in 1961.

They take a cuddly toy into the capsule as a mascot. When it floats into the air, it indicates when they reach space/weightlessness.

When human beings are strapped into extremely expensive rockets containing 274 tonnes of highly explosive rocket fuel, nothing is left to chance. This probably explains the strange rituals and superstitions performed by the Russian Space Agency.

Article

The strangest space launch rituals

Richard Hollingham, BBC Future Science, June 10, 2014

Keywords

Space, rocket, astronaut, cosmonaut, ritual, superstition, psychology, astronomy

Subject

Science, Earth and Space, ST2-9ES, ACSSU048, ST3-8ES, ACSSU078, SC4-12ES, ACSSU115, SC5-12ES, ACSSU188, SC5-17CW, ACSSU178, ACSSU179, ACSSU187

Spaceship from Earth lands on a comet

Astronomy

Did you know that the Philae spacecraft travelled 6.4 billion kilometres and 10 years to reach a comet?

It orbited around Earth 3 times and Mars once, using their gravity to fling it to speeds of 55,000 km/h.

When it arrived at the comet in 2014, it bounced off its surface twice (1 km into space) before attaching itself safely to the comet.

It was the European Space Agency’s Rosetta mission to visit the comet 67P (short for 67P/Churyumov-Gerasimenko).

It’s a large rubber duck-shaped chunk of ice covered by 10-20cm of dust.

The instruments on board Philae detected carbon-based organic molecules in the ice, similar to the building blocks of life on Earth.

However, isotope analysis of the hydrogen in the ice (ratio of deuterium to hydrogen) shows it’s not the same as Earth, suggesting that Earth’s water might not have come from comets as once thought.

Further research is needed to understand our solar system, where Earth’s water came from and how life on this planet began.

 

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Article

Comet landing named Physics World 2014 breakthrough of the year

By Hamish Johnston, Physicsworld.com

Keywords

Comet, space, spacecraft, Earth, Mars, solar system, water, hydrogen, deuterium, isotope, organic, carbon, Philae, Rosetta, gravity, orbit, speed

Subject

Science, Earth and Space, ST2-7(W, ACSSU076, ST3-8ES, ACSSU078, ST3-12MW, ACSSU077, ACSSU095, SC4-10PW, ACSSU118, SC4-12ES, ACSSU115, SC5-12ES, ACSSU188

Oldest rock on Earth is not from Earth

Astronomy, Geology

Did you know that the oldest rock on Earth is actually from Mars?

It’s called Black Beauty and it’s 4.4 billion years old.

It’s owned by a doctor/amateur meteorite collector from America.

It’s worth >$10,000 per gram (gold is ~$40 per gram) and he has ~800g of it.

Around 5 million years ago, an asteroid struck the surface of Mars, blasting the rock into space.

Then sometime within the last 1000 years, it landed on Earth as a meteorite (found by a nomad in the Western Sahara).

It’s particularly interesting because it’s a sedimentary rock containing water (from 4.4 billion years ago), therefore perfect for harbouring fossilised life forms (if there ever was life on Mars).

It’s currently being analysed by museums around the world.

 

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Article

Martian Obsession, by Eric Hand. Science, 2014. 346:1044-9.

Further Reading

Origin and age of the earliest Martian crust from meteorite NWA7533

Humayun et al., 2013 Nature 503:513-6

Keywords

Mars, Earth, space, meteorite, rock, sedimentary, water, fossil, asteroid

Subject

Science, Earth and Space, ST3-8ES, ACSSU078, SC4-12ES, ACSSU153, ACSSU115, SC5-12ES, ACSSU188, SC5-13ES, ACSSU180