Herschel’s ground station in Western Australia this afternoon found that the temperature in all of the telescope’s instruments is rising, confirming that the helium has run out. The depletion of the coolant was expected, as the 2300 litres of liquid helium inside the observatory had been evaporating since Herschel’s launch in 2009.

“Herschel has offered us a new view of the hitherto hidden Universe, pointing us to a previously unseen process of star birth and galaxy formation, and allowing us to trace water through the Universe from molecular clouds to newborn stars and their planet-forming discs and belts of comets,” said Göran Pilbratt, a Herschel Project Scientist at the ESA.

The telescope has been gazing into space for over three years. In just the past few months data from Herschel has been used to find starburst galaxies, examine a near-earth asteroid, discover massive comet belts, and link the 1994 Shoemaker-Levy 9 impact to water on Jupiter.

“Herschel has exceeded all expectations, providing us with an incredible treasure trove of data that that will keep astronomers busy for many years to come,” said Alvaro Giménez Cañete, Director of Science and Robotic Exploration at the ESA.

(Image courtesy ESA)

This week, NASA revealed that Saturn has now been added to the short list of places in the Solar System where astronomers have been able to observe collisions occurring as they happen (Earth, the moon, and Jupiter are the others).

NASA’s Cassini probe has captured images of meteoroids hitting the debris that makes up Saturn’s rings. Researchers believe that studying the impact rate on Saturn can help them determine more precisely how the planets in the Solar System formed.

“These new results imply the current-day impact rates for small particles at Saturn are about the same as those at Earth – two very different neighborhoods in our solar system – and this is exciting to see,” said Linda Spilker, a Cassini project scientist at NASA’s Jet Propulsion Laboratory (JPL). “It took Saturn’s rings acting like a giant meteoroid detector – 100 times the surface area of the Earth – and Cassini’s long-term tour of the Saturn system to address this question.”

Cassini scientists studied data for years to find evidence of the tracks the small meteorites left behind. The research has been published in the latest issue of the journal Science.

“We knew these little impacts were constantly occurring, but we didn’t know how big or how frequent they might be, and we didn’t necessarily expect them to take the form of spectacular shearing clouds,” said Matt Tiscareno, lead author of the paper and a Cassini participating scientist at Cornell University. “The sunlight shining edge-on to the rings at the Saturnian equinox acted like an anti-cloaking device, so these usually invisible features became plain to see.”

(Image courtesy NASA/JPL-Caltech/Space Science Institute/Cornell)

The European Space Agency (ESA) today announced that the water in the Jovian planet’s upper atmosphere has been linked to the 1994 Shoemaker-Levy 9 impacts. The comet Shoemaker-Levy 9 broke up and collided with Jupiter in July of 1994. The week-long event, which was the first directly-seen extraterrestrial collision in the Solar System, was observed by astronomers around the world.

Though astronomers suspected the Shoemaker-Levy impacts were the source of the water, the ESA’s Herschel space observatory has now been able to map the vertical and horizontal distribution of the water in Jupiter’s atmosphere. The observatory’s infrared imaging was able to discern that there is two to three times more water in Jupiter’s southern hemisphere than in the northern hemisphere. Shoemaker-Levy hit Jupiter’s southern hemisphere, and Herschel has found “most” of the water is concentrated around the impact sites. The findings have been published in the journal Astronomy and Astrophysics.

“Only Herschel was able to provide the sensitive spectral imaging needed to find the missing link between Jupiter’s water and the 1994 impact of comet Shoemaker-Levy 9,” said Thibault Cavalié, lead author of the paper and an astrophysicist at the Laboratoire d’Astrophysique de Bordeaux. “The asymmetry between the two hemispheres suggests that water was delivered during a single event and rules out icy rings or moons as candidate sources.

“According to our models, as much as 95% of the water in the stratosphere is due to the comet impact.”

(Image courtesy ESA/Herschel/T. Cavalié et al./NASA/ESA/Reta Beebe)

NASA, on the other hand, has been staring straight into the sun for years now. The agency launched the Solar Dynamics Observatory (SDO) in 2010 to capture images of the sun, which it does every 12 seconds in 10 different wavelengths. Scientists are using the SDO to learn more about the sun and to improve predictions for solar flares and coronal mass ejections, which can affect satellites orbiting Earth.

In the three years since its launch, the SDO has observed the sun as it ramps up to “solar maximum,” which is the peak of the star’s 11-year solar activity cycle. To demonstrate this increase in the sun’s activity, NASA this week released a video that puts together many of the images taken by the SDO. The time-lapsed video shows two images of the sun per day for three years. It also has some nice background music (“A Lady’s Errand of Love” by Martin Lass).

The object, which orbits the star HD 100546, is only 335 light-years from Earth and appears to be a gas giant. If the findings, published this week in Astrophysical Journal Letters, are confirmed, they could provide evidence for hypotheses about how planets form.

“So far, planet formation has mostly been a topic tackled by computer simulations,” says Sascha Quanz, lead researcher on the project and a scientist at ETH Zurich. “If our discovery is indeed a forming planet, then for the first time scientists will be able to study the planet formation process and the interaction of a forming planet and its natal environment empirically at a very early stage.”

For now, the planet has only been detected by the European Southern Observatory’s (ESO) Very Large Telescope as a blob orbiting within the star’s accretion disc. The research team also detected “structures” in the dust cloud near the object as well as an increased temperature that could be caused by planet formation. Current planet-formation hypotheses hold that planets form from the gas and dust that are left over after a star forms.

“Exoplanet research is one of the most exciting new frontiers in astronomy, and direct imaging of planets is still a new field, greatly benefiting from recent improvements in instruments and data analysis methods,” said Adam Amare, a member of the research team. “In this research we used data analysis techniques developed for cosmological research, showing that cross-fertilisation of ideas between fields can lead to extraordinary progress.”

(Image courtesy ESA)

Using NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) and the ESA’s XMM-Newton, astronomers were able to observe the black hole that lies at the center of the galaxy NGC 1365. The object was found to be spinning nearly as fast as physics will allow, providing researchers with new information about how black holes behave.

“This is hugely important to the field of black hole science,” said Lou Kaluzienski, a NuSTAR program scientist at NASA Headquarters.

The measurements, to be published in the journal Nature, also provide clear evidence for Einstein’s theory of general relativity. The data shows that X-rays around the black hole are being warped by the object’s high gravity.

“We can trace matter as it swirls into a black hole using X-rays emitted from regions very close to the black hole,” said Fiona Harrison, coauthor of a new study, NuSTAR principal investigator of the California Institute of Technology in Pasadena. “The radiation we see is warped and distorted by the motions of particles and the black hole’s incredibly strong gravity.”

Both the NuSTAR and XMM-Newton telescopes were needed to penetrate the gas clouds that obscure NGC 1365′s center. NuSTAR detects high-energy X-ray radiation, while the XMM-Newton detects lower-energy X-rays. By simultaneously observing the X-rays emitted by iron in the black hole’s accretion disc, the telescopes were able to determine that the X-ray distortion was coming from the black hole instead of gas clouds. This means that astronomers can now use iron signature distortions to measure black hole spin rates.

“If I could have added one instrument to XMM-Newton, it would have been a telescope like NuSTAR,” said Norbert Schartel, XMM-Newton Project Scientist at the European Space Astronomy Center. “The high-energy X-rays provided an essential missing puzzle piece for solving this problem.”

(Image courtesy NASA/JPL-Caltech)

This week, astronomers revealed that a new system has been found that contains planets smaller than Earth. The new data has been presented in a paper published recently in the journal Nature.

The planets orbit around a star called Kepler-37, located around 210 light-years from our solar system. The smallest of the planest found, known as Kepler-37b, is only one-third the size of Earth – smaller than the planet Mercury and just slightly larger than Earth’s moon. The planet is not presumed to have an atmosphere, and scientists predict that life on the planet isn’t likely.

“Even Kepler can only detect such a tiny world around the brightest stars it observes,” said Jack Lissauer, planetary scientist at NASA‘s Ames Research Center. “The fact we’ve discovered tiny Kepler-37b suggests such little planets are common, and more planetary wonders await as we continue to gather and analyze additional data.”

Two other planets were found in the Kepler-37 system. Kepler-37c orbits further out and is slightly smaller than Venus, or around three-quarters the size of Earth. Kepler-37d is the furthest planet out, and is around twice the size of Earth. Kepler-37 itself is slightly smaller and cooler than the sun.

All three of the planets orbit Kepler-37 at less than than the distance between the sun and Mercury. They each also orbit their star in 40 days or less. The surface temperature of Kepler-37b is estimated to be higher than 800 degrees Fahrenheit.

“We uncovered a planet smaller than any in our solar system orbiting one of the few stars that is both bright and quiet, where signal detection was possible,” said Thomas Barclay, lead author of the paper and a Kepler scientist at the Bay Area Environmental Research Institute. “This discovery shows close-in planets can be smaller, as well as much larger, than planets orbiting our sun.”

(Image courtesy NASA/Ames/JPL-Caltech

The findings, published this week in the journal Nature Physics, show how certain kinds of solar winds can accelerate electrons. NASA in a statement today said that solar wind around Saturn’s magnetic field forms a shockwave that Cassini can use to study the particle acceleration effect.

“Cassini has essentially given us the capability of studying the nature of a supernova shock in situ in our own solar system, bridging the gap to distant high-energy astrophysical phenomena that are usually only studied remotely,” said Adam Masters, lead researcher on the paper and a researcher at the Institute of Space and Astronautical Science.

The detection of electron acceleration around Saturn came just as a strong shockwave was detected by Cassini. The researchers are looking for “quasi-parallel” shockwaves, which occur when a magnetic field and the direction of the shock are closely aligned.

Shockwaves, such as those from a supernova or solar wind, are common in the universe. When they hit magnetic fields with certain orientations, particles from the shockwave can be accelerated to close the speed of light. These interactions, scientists believe, could be the source of much of the cosmic rays seen in the universe.

(Image courtesy ESA)

Not just Copernicus, of course. Heliocentrism wasn’t his idea – it was proposed as early as the 3rd century BC. But Copernicus is credited with forming the comprehensive mathematical heliocentric model and his book De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) is considered one of the most important works in the history of science.

After the publication of Celestial Spheres, the so-called Copernican Revolution began, ushering the world into the Scientific Revolution.

Copernicus, a true Renaissance Man, served as a mathematician, astronomer, Catholic cleric, artist, physician, economist, and is said to have spoken at least four languages.

Copernicus was born on February 19th, 1473 and died in 1543 at the age of 70. Today’s animated Google Doodle celebrates his 540th birthday.

With the asteroid’s approach so near and the public’s growing awareness of the event, NASA has released another video to try and reassure people that doomsday is not on the way. It’s similar to the “Why the World Didn’t End Yesterday” video the agency released more than a week before the Maya Apocalypse doomsday scenarios predictably fell flat. Besides the obvious duty to assuage public fears, it’s clear NASA finds it valuable to have a record of using science to make predictions that actually come true.

The new video features James Green, director of NASA’s Planetary Science Division, and Dante Lauretta, principal investigator for the OSIRIS-REx mission, describing just how scientists know da14 isn’t a danger (hint: they use math) and what an exciting event today’s record-setting close flyby is for astronomers. The OSIRIS-REx mission is scheduled to launch a probe in 2016 that will visit an asteroid that actually might hit the Earth in the late 22nd century.

NASA will be streaming live commentary of the asteroid’s approach starting at 2 pm EST.