This is one of the first of our shiny new Discover galleries, loaded with great Leviathan pics. The full article is below.

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In today’s oceans, killer whales hunt other species of whales, working in packs to take down their much bigger prey. But living whales have it easy. Those that swam off the coast of Peru around 12 million years ago were hunted by a far bigger predator, a recently discovered animal with a very appropriate name: Leviathan.

Leviathan melvillei, named after the Biblical sea monster and the author of Moby Dick, was a giant sperm whale that has just been discovered by Belgian scientist Olivier Lambert. At between 13.5 and 18.5 metres in length, it was no bigger than the modern sperm whale, but it was clearly far more formidable.

Today’s sperm whale has no functional teeth in its upper jaw and only small ones in its lower jaw (which are mostly used in fights). It feeds through suction, relying on a rush of water to carry its prey into its open mouth. But Leviathan’s mouth was full of huge teeth, the largest of which were a foot long and around 4 inches wide. This was no suction feeder! Leviathan clearly grabbed its prey with a powerful bite, inflicting deep wounds and tearing off flesh as killer whales do, but with a skull three times bigger.

Leviathan was at the very top of the food chain and it must have needed a lot of food. While modern sperm whales mainly eat squid, Lambert thinks that Leviathan used its fearsome teeth to kill its own kind – the giant baleen whales. At the same point in prehistory, baleen whales started becoming much bigger and they were certainly the most common large animals in the area that Leviathan lived in. Lambert thinks that the giant predator evolved to take advantage of this rich source of energy. He says, “We think that medium-size baleen whales, rich in fat, would have been very convenient prey for Leviathan.”

It’s perhaps no coincidence that the biggest shark in history – the mighty Megalodon – also appeared at the same time in the same part of the world. It too was thought to have hunted whales and many of its teeth have also been found at Cerro Colorado. For the moment, it’s hard to say if the two predators were direct competitors, since they may have swum in different parts of the Peruvian seas. Lambert speculates that the adults of either species could have eaten the young of the other but there’s no evidence for this yet.

In the last few years, other smaller prehistoric sperm whales have been found in Peru and Italy. Their powerful teeth told us that these predators bit their prey in the manner of killer whales. The teeth were generally quite small but, as early as 1877, fossil hunters have found much larger teeth that looked very much like those of a sperm whale. The teeth provided tantalising hints of a much bigger animal but they were never accompanied by an actual skull. Their owner remained an enigma.

Lambert set out to find that skull in 2006, leading several expeditions into Peru’s Pisco-Ica desert. The digs weren’t fruitful but the team’s luck took a turn for the amazing at the very end. “In November 2008, on the last day of the field trip, my Dutch colleague Klaas Post discovered a very large cetacean skull,” says Lambert. “Usually large skulls belong to baleen whales, but Klaas immediately noted enormous teeth, both on the upper and lower jaw.” They had found Leviathan.

The skull is beautifully adapted to capture large, powerful prey. The snout was short and wide, allowing it to bite more strongly with its front teeth and resist the struggles of its prey. Its temporal fossa – the shallow depression on the side of the skull – was enormous and could old huge jaw-closing muscles. The bite would have been the largest of any tetrapod (the animal group that includes mammals, birds, reptiles and amphibians). And the teeth were deeply embedded in the jaw bones for each support, and interlocked to give the animal a shearing, meat-carving bite. They were also angled forwards, giving Leviathan a better grip on prey with curved bodies.

The skull also creates a mystery. Sperm whales have a unique organ in their heads called the spermaceti, and Leviathan’s was particularly large. The spermaceti is full of a waxy substance that was originally thought to be the animal’s sperm (hence the name). Its purpose isn’t clear although there are many theories, all of which must now be considered in the light of Leviathan’s very different lifestyle.

The sperm whale might use it to control its buoyancy during a dive by pumping in cold water, solidifying the wax and increasing the density of its head. At the depths, the energy expended during a hunt heats up the wax and melts it again. But Leviathan probably didn’t hunt for squid and probably wasn’t a deep-diver like the modern sperm whale. In light of this, other explanations become more intriguing. The case containing the spermaceti could be used as a battering ram during fights. It could also boost the sperm whale’s echolocation, allowing it to stun its prey with sound, or woo females (the male’s organ is particularly big).

Reference: Nature http://dx.doi.org/10.1038/nature09067

More on ancient whales:

• Whales evolved from small aquatic hoofed ancestors
• Sperm whale poo offsets carbon by fertilising the oceans with iron
• Ever since there have been whales, there have been Osedax worms eating their bones
• Scientists, film-makers team up to expose illegal international trade in whale meat
• Echolocation in bats and whales based on same changes to same gene
• Fossil foetus shows that early whales gave birth on land

If the citation link isn’t working, read why here

When Japan’s Hayabusa space probe returned home from a sever-year odyssey this month, we got to see the amazing video as it broke up in a brilliant flash in the atmosphere and deposited its sample container (hopefully containing asteroid material) in Australia. Three high school students from Massachusetts, however, got a much better view. They experienced it first hand, and helped make that video for the world to see, thanks to a little white lie told by their teacher.

Ron Dantowitz of Brookline, Massachusetts, gave the three a challenge: If you had to track an object entering the atmosphere at 27,000 miles per hour, how would you know where to look, how would you keep the camera trained on the careening object, and what could you learn about the temperatures the object encountered? After they worked on the project for half a year, Dantowitz let loose his secret—this was no hypothetical scenario. He and the three students got to fly on the DC-8 over Australia and help NASA film Hayabusa’s return.

“We had flown several practices, but when we took off for the real thing, I felt a surge of adrenaline,” says [James] Breitmeyer. “I was on the edge of my seat, anxious for our plane to arrive at the right place at the right time.”

“We got to the rendezvous area 30 minutes ahead of time,” says Dantowitz. “So we practiced the rendezvous to make sure everyone knew which stars to line the cameras up with to capture Hayabusa’s re-entry. By the time we finished the trial run, we had only 2 or 3 minutes to go” [NASA Science News].

The students also captured spectral images like this one, showing how Hayabusa and its sample return container reacted with the atmosphere.

Concerning the mission itself, scientists at Japan’s space agency JAXA are slowly prying open the container to find out whether their plucky explorer captured any samples from its visit to an asteroid.

The presence of a low-pressure gas inside the capsule has already been detected, the agency is reporting. The nature of the gas, and whether it’s of extraterrestrial origin, has not yet been determined. The opening of the capsule is expected to take a week or more, though JAXA has not stated whether this is due to prudence on the part of the scientists or simply being unable to pry the darn package open [Popular Science].

We hope they find something inside. It would be the first time a probe has brought back samples from an asteroid it visited. And Hayabusa’s return after a long and troubled journey has inspired the Japanese government to pledge the funds for a sequel, the Washington Post reports.

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Image: NASA

Astronomers have confirmed that an object in an image from 2008 — thought at the time to possibly be a direct image of a planet orbiting another star — is in fact a planet.

I’ll explain in a sec, but I want people to understand that this discovery is being touted as the first direct image of a planet around another star. It isn’t. Nor is it the first direct image of a planet orbiting a sun-like star. What this is is the first direct image of a planet orbiting a sun-like star taken using a ground-based telescope. While that may sound overly picky, it’s actually a significant achievement, and worth noting.

First, the planet picture:

This image, taken in 2008 by the Gemini North telescope in Hawaii, shows the star 1RXS J160929.1-210524 (I’ll call it 1RXS 1609) in the center, and the planet (1RXS 1609b) indicated by the red circle. As I wrote about this in 2008:

The image come from the monster 8 meter Gemini North telescope in Hawaii. The star is 1RSX J160929.1-210524 (for those taking notes at home) — it’s a K7 dwarf, a bit cooler and smaller than the Sun — and the planet is the blip circled at the upper left. It has no real name as yet — it hasn’t been confirmed yet; more on that in a sec — but if it’s a planet orbiting the star, it has a mass of about 8 times that of Jupiter.

The problem was, it might have been a background galaxy or another, fainter star. It’s happened before; I spent weeks working on a similar image from Hubble that turned out to be a background star (grrr). However, new images revealed the object is in fact orbiting the star, and is a planet. Here’s the proof:

On this plot, the separation of the star and object are shown on the y-axis, and time on the x. The star is very slowly moving across the sky as it orbits the center of our galaxy. If the object were a background star, moving at a different rate, the separation between it and the star would fall on or near the purple line, changing as they move separately. If the object were a planet, the separation wouldn’t change much at all as they traveled together across the sky. The observations of the object are shown as black dots, and fall pretty much right on the line marking it as a planet.

Cool!

Given these observations, and the distance of the star of about 500 light years, we know the planet 1RXS 1609b has about 8 times the mass of Jupiter, orbits the star 45 billion km (27 billion miles) from its star — 300 times the Earth-Sun distance — and has a temperature of 1500 C (2700° F). The star is a bit less massive than the Sun, and isn’t nearly hot enough to heat the planet to that temperature. The reason the planet is hot is because it’s young, only 5 million years old. It’s still cooling off from being formed, and in a few billion years will be very cold. But right now it’s warm enough to glow and be detected by us.

This discovery is a technological achievement because the star and planet are very close together in the sky, and difficult to separate. From the ground, the Earth’s atmosphere blurs the images and scatters the star’s light, making the planet extremely hard to see at all. Even more amazing is that they could get an actual spectrum of the planet and use that to determine its temperature; that’s even harder to do (like juggling is hard, but doing it on a unicycle even harder). So all in all, a truly remarkable event.

However, as I pointed out, it’s not being reported completely accurately.

First, it’s not the first exoplanet even seen directly. That distinction belongs to the planet 2M1207b, which orbits a brown dwarf about 230 light years away. Brown dwarfs are smaller and cooler than the Sun, and are not fusing hydrogen into helium in their cores, so some people don’t consider them to be real stars. So while the object seen is a planet, it’s not orbiting a sun-like star.

OK, but a planet already has been directly imaged orbiting the star Fomalhaut. That star is hotter and more massive than the Sun, but is far more sun-like than a brown dwarf. The first image of the planet Fomalhaut b was taken in 2004 using Hubble Space Telescope, and the second confirming image in 2006. It took two more years to make sure everything was correct, and the news announced in 2008. So while this was announced after the image of 1RXS 1609b was first taken in 2008, the first image of Fomalhaut b was taken in 2004, four years earlier.

So some people are saying this observation of 1RXS 1609b is the first direct image of a planet orbiting a sun-like star taken by a telescope on Earth (Hubble is orbiting in space). I’ll grant that. And while that may seem a bit nit picky, it’s actually pretty cool. Observing exoplanets from space is in some ways easier than from the ground, because there’s no air to screw up the image. It’s still incredibly hard, but easier. From the ground, though, there are techniques that improve the odds a lot. Still, these are very difficult observations and are a fantastic achievement.

I’ve seen this reported with inaccurate headlines all over the place, so please be aware that there are misleading and even exaggerated reports about this. But also keep in mind that despite the breathless hyperbole, this really is pretty cool news.

“Peacekeeper” missiles are getting a new lease on life: as satellite launchers. Next week, NASA plans to launch the second of these decommissioned intercontinental ballistic missiles, renamed “Minotaur IV,” to deploy a trash-tracking satellite.

It’s nice to know that one relic will help NASA spot others–pieces of junk, like abandoned rocket stages left over from other space missions. As the IV in the new rocket’s name implies, the Peacekeeper isn’t the first retired missile to enter the Air Force’s very special recycling program. The first Minotaurs (pdf) incorporated stages from Minutemen missiles.

Barron Beneski is a representative of Orbital Sciences Corp., which holds the Air Force contract to transform the missiles into launch vehicles. Beneski told Discovery News:

“What is neat is that what was once a military weapons system is now a peaceful use of government assets. It’s the whole idea of turning ’swords into plowshares.’”

Other countries, notably Russia and China, have similar missile makeover programs. Unlike these countries, the United States does not offer the boosters for sale on the open market–only for government use.

“OSC (Orbital Sciences) can’t sell a Minotaur to Brazil,” Wayne Eleazer, a retired Air Force officer, told Discovery News. “That’s still not allowed.”

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Image: NASA/JPL