Thierry Legault: Moonbow and Meteor over Australia’s Wallaman Falls

Night vision under a full Moon at Wallaman Falls in Queensland, Australia. Credit and copyright: Thierry Legault. Used by permission.

Astrophotographer extraordinaire Thierry Legault traveled to Australia for the Transit of Venus this past June, but he didn’t stop with just taking incredible images of the Transit and then head home to France. He’s just published an wonderful collection of night sky images he took from his time in Australia, including this beautifully stunning image of a ‘Moonbow’ over Wallaman Falls, located in between Townsville and Cairns in north Queensland. If you’ve not seen a Moonbow before, you’re probably not alone. Many times, they are only visible in long exposure photographs, as the Moonlight effect is usually too faint for human eyes to discern. But the Moonlight on the water mist from the falls creates a Moonbow.

“The gibbous Moon makes a Moonbow over the falls while a bright meteor crosses the Milky Way,” Thierry wrote to Universe Today, sharing his new images. “Other visitors were sleeping in the camping area, but not me!”

See his entire collection of his Australian Nights images from June 2012 — they’re simply wonderful, and confirms the beauty of the night sky from down under!

Fires in the Sky, Fires on the Ground

 

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With all of the activity that’s been occurring on the Sun recently, the aurorae have been exceptionally bright and have created quite a show to viewers – both on Earth as well as above it!

The image above was taken over the southern Indian Ocean by astronauts aboard the International Space Station. The southern lights – a.k.a. aurora australis – glow bright green and red in the upper layers of the atmosphere, creating a dazzling aerial display. (Click here to watch a movie of this.)

Shortly after, fires can be seen on the ground as the ISS passes over Australia:

Wildfires in Australia seen from orbit. Credit: NASA.

From NASA’s Earth Observatory website:

Astronauts on the International Space Station (ISS) used a digital camera to capture several hundred photographs of the aurora australis, or “southern lights,” while passing over the Indian Ocean on September 17, 2011. You can see the flowing ribbons and rays below as the ISS passed from south of Madagascar to just north of Australia between 17:22 and 17:45 Universal Time. Solar panels and other sections of the ISS fill some of the upper right side of the photograph.

Auroras are a spectacular sign that our planet is electrically and magnetically connected to the Sun. These light shows are provoked by energy from the Sun and fueled by electrically charged particles trapped in Earth’s magnetic field, or magnetosphere. In this case, the space around Earth was stirred up by an explosion of hot, ionized gas from the Sun — a coronal mass ejection — that left the Sun on September 14, 2011.

In the second image above, and in the last frames of the movie, light from the ground replaces the light show in the sky. Wildfires and perhaps some intentionally set agricultural fires burn on the continent of Australia,with smoke plumes faintly visible in the night sky. A gold and green halo of atmospheric airglow hangs above the horizon in the distance.

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Airglow is created by particles in the upper atmosphere that have been charged by UV light from the Sun during the day releasing the energy at night as greenish-yellow visible light.

Fires on the ground, fires in the sky… the stars blazing all around, the Sun in its full glory and a never-ending view of our entire planet… what an incredible place the ISS must be to work in! Absolutely amazing!

And the skies of night were alive with light, with a throbbing, thrilling flame; Amber and rose and violet, opal and gold it came. It swept the sky like a giant scythe, it quivered back to a wedge; Argently bright, it cleft the night with a wavy golden edge.

— “The Ballad of the Northern Lights”, Robert Service

Read more on the NASA Earth Observatory.

Researchers Discover 2nd Largest Impact Crater in Australia

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Geothermal energy researchers from the University of Queensland in Australia have identified what may be the second largest meteorite impact crater in Australia. Dr. Tonguç Uysal of the University of Queensland and Dr. Andrew Glikson of Australian National University identified rock structures that appear to have formed because of the shock of a meteorite impact. Their discovery was made while doing geothermal energy research in the Cooper Basin, which lies on the border between Queensland and South Australia.

The meteorite that caused the impact was likely 8 to 12 km in diameter (5 to 7.5 miles), Dr. Glikson said in an interview. It is also possible that a cluster of smaller meteorites impacted the region, so further testing is needed to pin down the exact nature of the impactor. The impact likely occurred over 300 million years ago, and the shock of the impact altered rock in a zone 80 km (50 miles) in diameter.

Dr. Glikson said, “Dr Uysal is studying the geochemistry and isotopes of granites from the basement below the Cooper Basin and observed potential shock lamella in the quartz grains.” Distinctive features of a shock due to a violent event such as a volcanic eruption, meteorite impact or earthquake are preserved in the rock surrounding such an event. In the case of the Cooper Basin impact, “penetrative intracrystalline planar deformation features” – essentially microscopic lines oriented in the same direction – were discovered in quartz grains. Additionally, the magnetic orientation of some of the rocks is slightly altered, further evidence of an impact event.

The impact structure itself may extend 10,000 square kilometers ( 3,850 square miles) and 524 meters (1,700 feet) deep, though Dr. Glikson said that further studies of the area include, “Studies of the geophysical structure of the basement below the Cooper Basin aimed at defining the impact structure.”

There is significant interest in the Cooper Basin as a source of geothermal energy, and there are several oil and gas companies currently mining the region, which is an important on-shore repository of petroleum. The impact event is likely the reason why this region is such a hotspot for geothermal activity.

“Large impacts result in a hydrothermal cell (boiling of ground water) which effect redistribution and re-concentration of K [potassium], Th [thorium] and U [uranium] upwards in the crust, hence elevated generation of heat from crustal zones enriched in the radiogenic elements,” Dr. Glikson explained.

The recent discovery of this impact crater makes it the second largest in Australia, second only to the Woodleigh impact structure (120 km in diameter), which was produced by an asteroid 6 to 12 km (4 to 8 miles) across, about 360 million years ago.

Dr. Glikson and Dr. Uysal will be presenting their findings at the upcoming Australian Geothermal Energy Conference in Adelaide, which runs from the 16th – 19th of November. They also plan to have their results published in a peer-reviewed journal, Dr. Glikson said. You can read a preliminary abstract of their conference paper here.

Source: Queensland University press release, conference paper abstract, interview with Dr. Andrew Glikson

Australia Pictures

View Of Australia From Galileo

One of the best ways to appreciate Australia is to see it from space. Here are some cool Australia pictures captured by satellites.

This is an image of Australia captured by NASA’s Galileo spacecraft as it was speeding away from Earth towards its final destination of Jupiter.

Australia West Coast

Here’s a photo of the West Coast of Australia captured by the MODIS sensor on board NASA’s Terra satellite. This image shows how Australia can have red deserts, agricultural regions and spectacular coastlines.

Southwest Australia

This is an image of Southwest Australia captured by NASA’s Terra satellite. It shows the continent’s deserts but also its old growth forest near the coast.

Southern Australia

This is a photo of South-Central Australia, which is home to several of the continent’s many deserts. The white regions in this photograph are some of Australia’s dry salt lake beds.

Spider Crater, Western Australia

This is a photograph of Spider Crater in Western Australia. Scientists think the crater was formed between 600 and 900 million years ago.

We’ve written many articles about Australia for Universe Today. Here’s an article about a giant iceberg that was headed for Australia, and here’s an article about a huge river of dust above Australia.

If you’d like more info on Australia, check out the site for NASA’s radio telescope in Australia, and here’s and article about bushfires in Australia.

We’ve recorded an entire episode of Astronomy Cast about Earth. Listen here, Episode 51: Earth.