Organic molecules discovery on comet


This 13 November 2014 video is called Rosetta Comet Landing: Philae send first image of 67P.

From daily The Guardian in Britain:

Philae lander detects organic molecules on surface of comet

Spacecraft beams back evidence of carbon and hydrogen that could provide clues about origins of life on Earth

Richard Gray

Tuesday 18 November 2014 22.58 GMT

The Philae lander has found organic molecules – which are essential for life – on the surface of the comet where it touched down last week.

The spacecraft managed to beam back evidence of the carbon and hydrogen–containing chemicals shortly before it entered hibernation mode to conserve falling power supplies.

Although scientists are still to reveal what kind of molecules have been found on comet 67P/Churyumov-Gerasimenko, the discovery could provide new clues about how the early chemical ingredients that led to life on Earth arrived on the planet.

Many scientists believe they may have been carried here on an asteroid or comet that collided with the Earth during its early history.

The DLR German Aerospace Centre, which built the Cosac instrument, confirmed it had found organic molecules.

It said in a statement: “Cosac was able to ‘sniff’ the atmosphere and detect the first organic molecules after landing. Analysis of the spectra and the identification of the molecules are continuing.”

The compounds were picked up by the instrument, which is designed to “sniff” the comet’s thin atmosphere, shortly before the lander was powered down.

It is believed that attempts to analyse soil drilled from the comet’s surface with Cosac were not successful.

Philae was able to work for more than 60 hours on the comet, which is more than 500m miles from Earth, before entering hibernation.

“We currently have no information on the quantity and weight of the soil sample,” said Fred Goesmann principal investigator on the Cosac instrument at the Max Planck Institute for Solar System Research.

Goesmann said his team were still trying to interpret the results, which will hopefully reveal whether the molecules contain other chemical elements deemed important for life.

Professor John Zarnecki, a space scientist at the Open University who was the deputy principal investigator on another of Philae’s instruments, described the discovery as “fascinating”.

“There has long been indirect evidence of organic molecules on comets as carbon, hydrogen and oxygen atoms have been found in comet dust,” he said.

“It has not been possible to see if these are forming complex compounds before and if this is what has been found then it is a tremendous discovery.”

Organic molecules, which are chemical compounds that contain carbon and hydrogen, form the basic building blocks of all living organisms on Earth.

They can take many forms from simple small molecules like methane gas to complex amino acids that make up proteins.

Philae landed on comet 67P/Churyumov–Gerasimenko after a 10-year journey through space aboard the Rosetta space probe. Philae’s initial attempt to touch down on the comet’s surface were unsuccessful when it failed to anchor itself properly, causing it to bounce back into space twice before finally coming to rest.

It meant the lander’s final resting place was about half a mile from the initial landing site and left Philae lying at an angle and its solar panels partially obscured.

In a desperate attempt to get as much science from the lander as possible before its meagre battery reserves ran out, scientists deployed a drill to bore down into the comet surface.

It is thought, however, that the drilling was unsuccessful and it failed to make contact with the comet.

But other findings from instruments on the lander, which were beamed back shortly before it powered down into a hibernation mode, suggest that the comet is largely composed of water ice that is covered in a thin layer of dust.

Preliminary results from the Mupus instrument, which deployed a hammer to the comet after Philae’s landing, suggest there is a layer of dust 10-20cm thick on the surface.

Beneath that is very hard water ice, which Mupus data suggests is possibly as hard as sandstone.

“It’s within a very broad spectrum of ice models. It was harder than expected at that location, but it’s still within bounds,” said Professor Mark McCaughrean, senior science adviser to Esa.

“You can’t rule out rock, but if you look at the global story, we know the overall density of the comet is 0.4g/cubic cm. There’s no way the thing’s made of rock.”

At Philae’s final landing spot, the Mupus probe recorded a temperature of –153°C before it was deployed and then once it was deployed the sensors cooled further by 10°C within half an hour.

“If we compare the data with laboratory measurements, we think that the probe encountered a hard surface with strength comparable to that of solid ice,” said Tilman Spohn, principal investigator for Mupus. Scientists hope that as comet 67P/Churyumov-Gerasimenko moves closer to the sun in the next few months, some light will start to reach Philae’s solar panels again, giving it enough power to come out of hibernation.

This could allow further analysis to take place on the surface.

“Until then we are going to have to make do with the data we have got,” said Zarnecki.

The Philae spacecraft may not be dead quite yet.

Meteor shower in the USA tonight


This video says about itself:

Brilliant Leonids Meteor Shower November 17-18, 2014

6 November 2014

This year’s Leonids meteor shower peaks on the morning of Nov. 18. If forecasters are correct, the shower should produce a mild but pretty sprinkling of meteors. The waning crescent moon will not substantially interfere with viewing the Leonid shower.

Find a nearby location away from city lights, dressing warmly, and lie flat on your back and look straight up. No special viewing equipment needed — just your eyes.

For best viewing, wait until after midnight on Nov. 18, with the peak of the shower occurring just before sunrise.

You can see 10 to 15 meteors per hour.

Leonids are bits of debris from Comet Tempel-Tuttle. Every 33 years the comet visits the inner solar system and leaves a stream of dusty debris in its wake. Many of these streams have drifted across the November portion of Earth’s orbit. Whenever our planet hits one, meteors appear to be flying out of the constellation Leo.

Some years, the Leonids can produce hundreds of meteors an hour.

And some years, the Leonids produce not showers of meteors, but storms. In 1833, for example, so many meteors streaked across the sky that their light awakened sleeping Americans. And in 1966, the Leonids produced up to 50 meteors every second across parts of the southwest.

Read more here.

By Jacqueline Howard in the USA:

How To See The 2014 Leonid Meteor Shower

1/16/2014 8:59 am EST

Here’s another chance to wish upon a shooting star: the 2014 Leonid Meteor Shower will peak overnight between Nov. 17 and 18, filling the sky with at least a sprinkling of meteors. And since the moon will be a waning crescent, the sky should be dark enough for a decent viewing.

“We’re predicting 10 to 15 meteors per hour,” Dr. Bill Cooke of the Meteoroid Environment Office at NASA’s Marshall Space Flight Center, said in a written statement. “For best viewing, wait until after midnight on Nov. 18, with the peak of the shower occurring just before sunrise.”

For skywatchers who will be unable to watch the show in person, Slooh Space Camera will live-stream the shower starting at 8 p.m. EST .

Spacecraft landing on comet news update


This video says about itself:

STUNNING NEW ROSETTA IMAGES OF COMET 67P/Churyumov-Gerasimenko

7 August 2014

Please watch in 1080p

On August 3rd, the Rosetta spacecraft‘s narrow angle camera captured this stunning image of the nucleus of Comet 67P/Churyumov-Gerasimenko. After 10 years and 6.5 billion kilometers of travel along gravity assist trajectories looping through interplanetary space, Rosetta had approached to within 285 kilometers of its target. The curious double-lobed shape of the nucleus is revealed in amazing detail at an image resolution of 5.3 meters per pixel.

About 4 kilometers across, the comet nucleus is presently just over 400 million kilometers from Earth, between the orbits of Jupiter and Mars. Now the first spacecraft to achieve a delicate orbit around a comet, Rosetta will swing to within 50 kilometers and closer in the coming weeks, identifiying candidate sites for landing its probe Philae later this year.

From the European Space Agency:

Posted on 12/11/2014 by emily

Rosetta and Philae separation confirmed

The Philae lander has separated from the Rosetta orbiter, and is now on its way to becoming the first spacecraft to touch down on a comet.

Separation was confirmed at ESA’s Space Operation Centre, ESOC, in Darmstadt, Germany at 09:03 GMT / 10:03 CET. It takes the radio signals from the transmitter on Rosetta 28 minutes and 20 seconds to reach Earth, so separation actually occurred in space at 08:35 GMT / 09:35 CET.

The first signal from Philae is expected in around two hours, when the lander establishes a communication link with Rosetta. Philae cannot send its data to Earth directly – it must do it via Rosetta.

Once the link has been established, the lander will relay via Rosetta a status report of its health, along with the first science data. This will include images taken of the orbiter shortly after separation.

The descent to the surface of Comet 67P/Churyumov–Gerasimenko will take around seven hours, during which the lander will take measurements of the environment around the comet. It will also take images of the final moments of descent.

Confirmation of a successful touchdown is expected in a one-hour window centred on 17:02 GMT / 18:02 CET. The first image from the surface is expected some two hours later.

Follow the event live: esa.int/rosetta.

See also here. And here. And here.

European Space Agency’s Rosetta space probe on Wednesday successfully deployed its robotic lander Philae on the Comet 67P/Churyumov-Gerasimenko. This is the first time a spacecraft has ever landed on the surface of a comet. The mission was ten years in the making: here.

Rosetta: Philae tight landing spot on comet prompts tough decisions for Esa. Rosetta mission controllers must decide whether to risk making lander hop from shadow of cliff blocking sunlight to its solar panels: here.

Millions of people around the world greeted with enthusiasm the news this week that the Philae lander had successfully touched down on Comet 67P/Churyumov-Gerasimenko, a small and rocky celestial body half a billion kilometers from earth. A new milestone has been reached, with scientists for the first time able to conduct an on-the-spot analysis of a comet. During its sixty hours of operation, Philae’s nine instruments gathered information about the comet that will assist in answering long-standing questions about the history of the solar system. In particular, scientists hope that the mission will provide insight into the theory that comets are an early source of water and organic compounds on Earth. Though the lander has gone into hibernation from a lack of power, the results it has sent back are already providing insight into the comet’s composition: here.

Philae: life and times of a comet lander: here.

Mercury, hottest planet, ice discovery


This 29 November 2012 video from the USA is called UCLA Professor David Paige – New Evidence for Water Ice on Mercury.

From daily The Independent in Britain:

Water on Mercury photographed by Nasa for the first time in ‘permanently shadowed’ craters

Images confirm that the planet closest to the Sun has ‘recent’ water deposits

James Vincent

Friday 17 October 2014

Nasa has taken the first ever pictures of water ice on Mercury – the permanently-roasting planet closest to the Sun in our Solar System.

It might sound counter-intuitive to find ice on a planet where surface temperatures hit highs of 430 degrees Celsius every day (a Mercury day is equivalent to 58 Earth days) but impact craters on the poles permanently shadowed from the Sun have been found to provide some much needed shade.

Scientists have thought this might be the case since the mid-1990s, when radio telescopes scanning the planet found areas that strongly reflected radar signals (a good sign that ice is present) with this most recent study is the first to provide optical proof.

The scientist examined a number of impact craters situated around Mercury’s north pole (including the largest, Prokofiev, an indentation just under 70 miles wide) and found that the deposits were made surprisingly recently, with the boundaries of the ice defined by sharped edges not yet smoothed out by time.

“The sharp boundaries indicate that the volatile deposits at Mercury’s poles are geologically young,” wrote the study’s authors in the journal Geology, “and either are restored at the surface through an ongoing process or were delivered to the planet recently.”

If the water was ‘delivered recently’ then it could suggest new mechanisms in the distribution of water-ice in the Solar System – research that might have implications for our own Moon, which is also believed to contain water-ice in areas of permanent shadow.

“If you can understand why one body looks one way and another looks different, you gain insight into the process that’s behind it, which in turn is tied to the age and distribution of water ice in the solar system,” study lead author Nancy Chabot said. “This will be a very interesting line of inquiry going forward.”

Exoplanet weather research


This 1 October 2014 video is called A Weather Map for the Hot Jupiter Exoplanet WASP-43b.

From Popular Science:

Weather Of Wild Exoplanet Mapped Using Hubble Telescope

With scorching temperatures day and night, WASP-43b ain’t no place to live.

By Loren Grush

Posted 10.10.2014 at 2:00 pm

About 260 light years away from Earth, there is a wild exoplanet about the size of Jupiter — but with double its mass. Known as WASP-43b, this huge planet orbits its host star, an orange dwarf, in just 19 short hours, meaning its “years” are shorter than Earth’s days.

Oh, did we mention it’s unbelievably hot? Just like the Moon, WASP-43b is tidally locked to its parent star, so one side of the planet is in perpetual light while the other side remains dark. On the day side, temperatures reach about 1,500 degrees Celsius (around 2,700 degrees Fahrenheit), which is hot enough to melt iron. The night side temperatures aren’t much better, reaching about 500 degrees Celsius (about 900 degrees Fahrenheit).

Well now, a team of researchers is learning even more about the crazy conditions on WASP-43b, providing vital clues as to how such a planet could have formed in the first place. Using the Hubble Space Telescope and two different forms of spectroscopy, the scientists have made detailed maps of the planet’s weather, as well as the amount of water in its atmosphere. They published their findings in two different studies in The Astrophysical Journal Letters.

Spectroscopy is an oft-used method for studying distant planets. It involves dissecting an object’s light into its component colors, revealing a lot about the object’s temperature, mass, water composition, and more.

In the first study, the researchers used a technique called transmission spectroscopy, in which they studied light from the orange dwarf as it filtered through WASP-43b’s atmosphere. By analyzing this light, they were able to figure out the amount of water in the planet’s atmosphere in the regions bordering the day and night hemispheres.

A technique known as emission spectroscopy was utilized for the second study, allowing the researchers to map the planet’s atmosphere at different longitudes. Using Hubble’s very precise instruments, they were able to subtract more than 99.95 percent of light from the host star, which enabled them to study light that was coming just from WASP-43b. They did this as the planet orbited the star, mapping the water abundance and element composition of the atmosphere at various longitudes along the way.

According to the researchers, all of the water in the planet’s atmosphere is vaporized. On Jupiter, water is condensed into icy clouds, but space probes have been unable to penetrate Jupiter’s atmosphere, so not much is known about its water abundance. Additionally, most of the water on the other planets in our solar system are trapped away as ice, making it difficult to study. Since all of WASP-43b’s water is in gas form, it’s much easier for researchers to measure.

Water is believed to play an important role in the formation of giant planets, and knowing the dispersion of water in WASP-43b’s atmosphere reveals a lot about how it formed. Many astronomers believe that asteroid-like bodies crash into these planets long ago when the planets were still quite young, delivering water and other molecules that we observe today.

Astronomy in October


Starry night in October

From eNature in the USA:

October’s Skies Are Great For Stargazing

Posted on Friday, September 26, 2014 by eNature

October skies are busy ones! The longer nights and cooler, clear skies of fall make for some great stargazing. And there’s a lot more than just stars to see up there!

Highlights Include Stars, Planets And Well-known Constellations

Our night sky sparkles with stars, billions of them, inspiring lovers, poets, explorers, and scientists. The closest star to Earth, the Sun, warms our planet and makes life possible.

Stars are composed mainly of hydrogen gas. Their light comes from the energy produced at their cores by nuclear fusion. This energy emerges from the surface of a star as the light we see and as ultraviolet light, X rays, and radio waves.

Our sun, which is at a stage in its life (called the main sequence stage) when it converts hydrogen at its core to helium and energy, maintains a fairly steady energy output. It’s been at this stage for about four and half billion years, and perhaps another five billion years remain until it uses up its hydrogen fuel. When a star becomes exhausted, the fuel at its center begins to expand and its surface cools. Depending on its mass, the star then turns into a red giant or a supergiant. Our sun will become a red giant.

In a red giant, both helium and hydrogen are transmuted into heavier elements and energy. After swelling to many times its former size and using up its store of helium, a red giant sheds its outer envelope. The star’s interior begins to shrink, and its surface heats up, becoming white hot. It’s now a white dwarf, an extremely dense star with the approximate mass of the Sun compressed into a size about that of the Earth. A teaspoonful of the matter of such a star would weigh many tons.

October Constellations

The Summer Triangle still graces the sky in early fall. At 9:00 p.m. on October evenings, it lies in the northwestern quadrant of the celestial dome. One corner, Altair, the alpha (or brightest) star in the constellation Aquila, the Eagle, is almost due west. Vega, the blue-white alpha star in the constellation Lyra, the Harp, is about halfway up the northwestern sky. The third corner, marked by Deneb, the brightest star of Cygnus, the Swan, is about two-thirds of the way between the horizon and the zenith (the point straight overhead).

Hercules, the Strongman, lies low in the northwest, just below Vega. Ursa Major, the Great Bear, and its well-known asterism (a star shape within a larger constellation), the Big Dipper, are very low on the northern horizon. The Little Dipper, or Ursa Minor (the Little Bear), extends to the left of Polaris, the North Star, which marks the end of its handle.

In the northeastern quarter of the sky is Andromeda, the Princess. Nearby are her mother, Queen Cassiopeia, whose wide W shape is now angled like a number 3, and her father, King Cepheus, shaped like a child’s drawing of a house. Below the Princess and the Queen is Perseus, the Hero, who saved Andromeda from Cetus, the Sea Monster. The brightest stars in this part of the sky are the yellowish star Cappella, the alpha star in the pentagonal constellation Auriga, the Charioteer, and the reddish star Aldebaran, marking the eye of Taurus the Bull, low in the east. The V-shaped star cluster of the Hyades looks like an arrowhead pointing to the right. Aldebaran sits at the end of the bottom arm of the V. Above Aldebaran is the small but beautiful star cluster of the Pleiades, also known as the Seven Sisters.

High in the south and southeast are the stars of Pegasus, the Winged Horse ridden by Perseus. The curved, narrow A shape of Andromeda begins at the northeastern corner of an asterism called the Great Square of Pegasus and stretches into the northeastern sky. On a very dark, clear night you might be able to make out a fuzzy patch of light above the middle of the two lines of stars that form Andromeda; this is the Great Andromeda Galaxy, the most distant object the eye can see unaided by binoculars or a telescope.

Closer to the horizon in the southern part of the sky are Pisces, the Fish, and below it, the dim constellation Cetus, the Sea Monster. Culminating in the south is Aquarius, the Water Bearer. Capricornus, the Sea Goat, and some of the other faint “watery” constellations, including little Delphinus, the Dolphin, are in the southwest. Almost due south is one of the brightest stars in the sky, Fomalhaut, the alpha star in Piscis Austrinus, the Southern Fish. Fomalhaut is unfamiliar to most northern-latitude observers since it belongs to a Southern Hemisphere constellation that appears in northern skies only briefly and always low. There are no other bright stars in the southern sky at this time, so it’s unmistakable.