Posts Tagged ‘Astronomy’

First Direct Evidence of Collision That Formed Moon

June 6, 2014

Newly analyzed lunar rocks have revealed the first direct evidence of the ancient smashup that created the moon, bolstering a long-held theory.

Theia smashes Earth

The rocks were gathered by astronauts on NASA’s Apollo missions. But newer scanning electron microscopes have now allowed scientists to detect in them the first chemical traces of the Mars-size planet thought to have blasted the proto-Earth around 4.5 billion years ago.

When the ancient planet, Theia, smashed into Earth, it blasted debris into space. The moon formed out of that debris. If the moon formed predominantly from the fragments of Theia, as predicted by most numerical models, the Earth and Moon should differ. This new analysis has provided evidence of this difference. Learn more here.

Jupiter’s Great Red Spot is Shrinking

May 17, 2014

Jupiter’s Great Red Spot — one of the most iconic and well known features in the solar system — is shrinking, and nobody knows why.

Great Red Spot is Shrinking

The so-called “Great Red Spot” is a violent storm, which in the late 1800s was estimated to be about 40,000 kilometres in diameter – wide enough for three Earths to fit side by side.

The storm, which is the biggest in the solar system, appears as a deep red orb surrounded by layers of pale yellow, orange and white.

Winds inside the storm have been measured at several hundreds of kilometres per hour.

By the time NASA’s Voyager space probes flew by in 1979 and 1980, the spot was down to about 22,500 kilometres across.

Now, new pictures taken by the Earth-orbiting Hubble Space Telescope show Jupiter’s red spot is smaller than it has ever been, measuring less than 16,100 kilometres in diameter. It also appears more circular in shape.

Scientists aren’t sure why the Great Red Spot is shrinking by about 1000 kilometres a year. Learn more here, here or here.

New Exoplanet Could Be Earth’s Cousin

April 18, 2014

Astronomers have found the first Earth-sized exoplanet within a star’s habitable zone. The planet is the closest thing yet to the coveted ‘Goldilocks’ orb that scientists have long sought — a world roughly the size of Earth orbiting a star at a distance that is just right for liquid water to exist.


Named Kepler-186f, the planet orbits a star that is less than half the size of the sun and much cooler. The new world is the outermost of five planets orbiting Kepler-186, a red dwarf star some 500 light-years from Earth.

Kepler-186f position

Learn more here, here, here, here or here.

Skydiver almost gets hit by a Meteorite

April 6, 2014

It sounds like an almost unbelievable: Anders Helstrup went skydiving nearly two years ago in Hedmark, Norway and while he didn’t realize it at the time, when he reviewed the footage taken by two cameras fixed to his helmet during the dive, he saw a rock plummet past him. He took it to experts and they realized he had captured a meteorite falling during its “dark flight” — when it has been slowed by atmospheric braking, and has cooled and is no longer luminous.

Skydiver Meteorite 1

Watch a video here or learn more here or here.

Fly through of a sliver of the universe

March 15, 2014

The Galaxy and Mass Assembly catalogue is a detailed map of the Universe showing where galaxies are in 3D. This simulated flythrough shows the real positions and images of the galaxies that have been mapped so far. Distances are to scale, but the galaxy images have been enlarged for your viewing pleasure.

Remember each little speck is an entire galaxy, not just a single star. Our Solar System’s star, the Sun, is merely one of the 100–400 billion stars in our galaxy The Milky Way.

Get ready to see an awful lot of galaxies …

Star is 1300 times bigger than sun

March 13, 2014

A monster version of our sun has been found, the largest known member of the family of yellow stars to which our sun belongs.

The whopper sun emits light in similar wavelengths as our sun but its diameter is over 1300 times larger. That means it would engulf all the planets between Mercury and Jupiter if placed at the centre of our solar system. The star’s size also means it is touching its smaller, companion star (see diagram, below).

HR 5171 A

Dubbed HR 5171 A, the star is located in the constellation Centaurus around 12,000 light years from Earth.

The two stars orbit each other, forming a binary system. However, though their centres are separated by more than the distance between our sun and Saturn, HR 5171 A is so large that the two are touching, forming a continuous peanut-shaped structure. Guess this star system ain’t big enough for two. Learn more here.

Kepler telescope discovers 715 new planets

February 28, 2014

NASA has announced a torrent of new planet discoveries, hailing a “bonanza” of 715 worlds now known outside the solar system thanks to the Kepler space telescope’s planet-hunting mission.


A new method for verifying potential planets led to the volume of new discoveries from Kepler, which aims to help humans search for other worlds that may be like Earth.

The 715 newly verified planets are orbiting 305 different stars.

The latest announcement brings the number of known planets to between 1500 and 1800, depending on which of the five main extra-solar planet-discovery catalogues is used. Learn more here.

Hand of God

January 12, 2014

Sometimes when you reach for the stars, the stars reach back. This cloud of gas and dust has been nicknamed the Hand of God, due to its eerie shape. The cloud is made of material that a star ejected when it exploded and is now being sculpted by the stellar core that remained.

Hand of God

More great images here.

Passing Shot of Earth Makes All Seem Tiny

December 12, 2013

A spacecraft drive-by has provided new footage of something we all take for granted – the orbit of the moon around Earth.

NASA’s Juno spacecraft has flown past our planet on its way to Jupiter, and managed to catch footage of the Moon as it performed an eternal tango with its hefty blue partner.

Juno used a gravitational slingshot manoeuvre to accelerate itself into the solar system after it was launched towards the asteroid belt in early August.

It received a boost in speed of more than 14,000 kph (about 7.3 kilometres per second), which set it on course for a July 4, 2016, rendezvous with Jupiter.

The spacecraft is equipped with an array of advanced sensors, including a special camera optimised for tracking faint stars, it was this camera that was trained towards Earth as the ship shot by, resulting in an intriguing, low-resolution glimpse of what we would look like to a visitor from afar.

Learn more here.

Aurora origins

November 8, 2013

On a dark night, far from the Equator, you might be lucky enough to spot an aurora: a shimmering, colourful glow in the sky. This natural light show has captivated people for thousands of years. While it is mostly associated with cold, dark nights near the poles, auroras have a much brighter, warmer origin: the Sun.

The extremely high temperatures of the solar surface produce plasma. Plasma isn’t a gas, solid or liquid. It’s a fourth state of matter, made up of charged particles also known as ions. The stream of plasma that shoots outwards from the Sun is called the solar wind.

The solar wind travels in all directions, and Earth is constantly being bombarded by fast-moving ions from the Sun. Earth has a magnetic field, so when the solar wind hits Earth, the charged particles are attracted to Earth’s magnetic poles.

As the ions move through Earth’s atmosphere, they collide with molecules of gas, such as oxygen and nitrogen. These collisions transfer energy from the ions to the gas molecules. The molecules are now in an excited state. To come back down to their unexcited state, the gas molecules release energy in the form of coloured light. This can be seen from Earth’s surface as an aurora.

The amount of solar activity varies. Sometimes there isn’t much solar wind, and an aurora isn’t visible. Peaks of solar activity occur roughly every 11 years, and it’s been about that long since the last one. Recently some large solar flares were detected on the Sun’s surface. This evidence suggests a solar maximum is approaching, which could result in brighter and more wide-spread auroras.

It is difficult to predict when an aurora will appear, and even when one does, it can move and disappear in an instant. Science can explain many aspects of auroras. However, their elusive and unpredictable nature combined with their beauty means they still seem somewhat magical. Learn more herehere or here.


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