Archive for the ‘NASA’ Category

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Ideal SETI-target planets and K-type stars

April 25, 2013

by tte-77

The Kepler-62 system – home to two habitable zone worlds. The small shining object to the right of Kepler-62f is Kepler-62e. Image credit: NASA Ames/JPL-Caltech.

Its been far too long since I contributed to Sky-Watching on a regular basis. On that sudden note here’s the first post in a while and its exoplanet related.

In the search for extraterrestrial life, NASA’s Kepler team have announced the discovery of Kepler-62 – a multiple planet system composed of five Earth and super-Earth sized planets, two of which are habitable zone worlds, orbiting an orange dwarf or to be precise a K-type main-sequence star.

Ok, so this is cool news right, and a K-type star too.  I’m intrigued.  Has Kepler found ideal SETI-target planets?

K-type stars are of particular interest in the search for other life because they are about three to four times as abundant as sun-like stars, making planet searches easier. K-type stars are also stable on the main sequence for a very long time, around 15 to 30 billion years which is two to three times longer than our own sun  and this may create an opportunity for life to evolve on the terrestrial planets orbiting them.

An artistic view of the system seen from Kepler-62f. Image credit: Danielle Futselaar/SETI Institute

The outermost planet, named Kepler-62f (see image) is about 1.4 times Earth’s radius and has a period of 267 Earth days. If Kepler-62f is a rocky planet with a similar atmosphere to Earth, sitting in the stars habitable zone it could host liquid water on its surface. Kepler-62e, also in the habitable zone is 1.6 times the Earth’s radius with a period of 122 Earth days, it could also host liquid water on its surface.

The authenticity of this multiple planet system was confirmed by a statistical analysis based on previous discoveries of multiple planets by Kepler as the detection of these planets was indirect.  The Kepler astronomers observed gradual loss of the host star’s brightness due to the passage of a planet in the line of sight, and not the planets themselves.  Speaking about the detection process Jason Rowe, Research Scientist at the Carl Sagan Center of the SETI Institute and co-author of the work said “Such calculations are only possible because of the thousands of additional transiting extrasolar planets that Kepler has discovered”.

About the discoveries Jon Jenkins,  Senior Scientist at the Carl Sagan Center of the SETI Institute and co-author of the work said “These discoveries move us farther down the road to discovering planets similar to Earth. While we don’t know if Kepler-62e and f are rocky or whether they have liquid water pooling on their surfaces, their existence shows that the incidence of small worlds in the habitable zone of Sun-like stars is high.

Thus we can look forward to the discovery and detailed characterization of Earth’s cousins in the years and decades to come by future missions and telescopes.”

So there you go – exoplanets, K-type stars, some smart scientists from the SETI Institute, nice images and a post with a final thought…

If Kepler has found ideal SETI-target planets, sort the funding and bring on the future missions and telescopes.

Sources: SETI / spacedaily.com

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Curiosity goes where water once flowed

September 28, 2012

by yaska77

NASA’s Curiosity rover has returned images showing evidence of an ancient, flowing stream on Mars after a close examination of two outcrops called “Hottah” and “Link”.

The rock outcrop shown below (named “Hottah” after Hottah Lake in Canada’s Northwest Territories) may look like broken up pavement, but it is actually exposed bedrock made up of smaller fragments cemented together.

This is what geologists call a “sedimentary conglomerate“. Scientists theorise that the bedrock was disrupted in the past (giving it the tilted angle) most likely through meteorite impacts.

NASA’s Curiosity rover has found evidence for ancient flowing streams on Mars at a few sites, including the rock outcrop pictured here (click to enlarge) – Credit: NASA/JPL-Caltech/MSSS

The key evidence for the ancient stream comes from the size and rounded shape of the gravel in and around the bedrock.

Hottah has pieces of gravel embedded in it, called clasts (one of which is circled above), up to a couple inches in size and located within a matrix of sand-sized material. Some of the clasts are round in shape, leading to the conclusion they were transported by a vigorous flow of water.

This set of images compares the Link outcrop of rocks on Mars on the left, with similar rocks seen on Earth on the right (click to enlarge) – Credit: NASA/JPL-Caltech/MSSS and PSI

The gravels in conglomerates at both outcrops range in size from a grain of sand to a golf ball. Some are angular, but many are rounded, and the similarity to pebbles found desposited in Earth’s streams and rivers is striking.

“The shapes tell you they were transported and the sizes tell you they couldn’t be transported by wind. They were transported by water flow,” said Curiosity science co-investigator Rebecca Williams of the Planetary Science Institute in Tucson, Arizona.

The finding site lies between the north rim of Gale Crater and the base of Mount Sharp, a mountain inside the crater which is Curiosity’s ultimate destination. Once there the rover will examine the sedimentary layers in the hope it will discover evidence of organic deposits, therefore confirming the past existance of life on Mars.

This is a truly exciting find!

Source: NASA MSL

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Hubble’s eXtreme view of the Universe

September 26, 2012

by yaska77

When it comes to looking into and imaging the past, the Hubble Space Telescope continues to produce shots of breathtaking wonder.

Called the eXtreme Deep Field, or XDF, the image below was assembled by combining 10 years of NASA Hubble Space Telescope photographs taken of a patch of sky at the center of the original Hubble Ultra Deep Field.

Astronomers have assembled a new, improved portrait of mankind’s deepest-ever view of the universe (click to enlarge) – Credit: NASA; ESA; G. Illingworth, D. Magee, and P. Oesch, University of California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09 Team

The Hubble Ultra Deep Field is an image of a small area of space in the constellation Fornax (latin for Furnace) located in the southern sky, far away from the glare of the Milky Way, and was created using Hubble Space Telescope data from 2003 and 2004.

By collecting faint light over many hours of observation (around 500 hours) it revealed thousands of galaxies, both nearby and very distant, making it the deepest image of the universe ever taken.

A finger held at arm’s length would appear to be about twice the width of the moon in this image (click to enlarge) – Credit: NASA/ESA and Z. Levay, STScI; Moon Image Credit: T. Rector/I. Dell’Antonio/NOAO/AURA/NSF

The new full-color XDF image contains about 5,500 galaxies even within its smaller field of view. The faintest galaxies are one ten-billionth the brightness of what the human eye can see.

The history of galaxies – from soon after the first galaxies were born to the great galaxies of today, like our Milky Way – is laid out in this one amazing image.

Garth Illingworth of the University of California at Santa Cruz (principal investigator of the Hubble Ultra Deep Field program) said, “The XDF is the deepest image of the sky ever obtained and reveals the faintest and most distant galaxies ever seen. XDF allows us to explore further back in time than ever before”.

It should certainly keep astronomers busy for a while, at least until the James Webb Space Telescope launches! With it’s specialised infrared instruments it is expected to find even fainter galaxies that existed when the universe was just a few hundred million years old.

You can read more details on the NASA Hubble Website here.  Galactic!

Source: NASA

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Latest Curiosity images from Mars

August 7, 2012

by yaska77

We promised you images and here are the latest batch from NASA JPL, sent from Curiosity over the last couple of days. We start first though with a fantastic image captured by the Mars Reconnaissance Orbiter and it’s HiRISE camera!

This image was taken just moments after Curiosity’s descent speed had slowed from thousands of kilometers per hour to just hundreds (click to enlarge) Credit: NASA/JPL-Caltech

In the expanded view you can see the band details on the “supersonic” parachute, and even the hole in the centre, as Curiosity heads towards a famous landing! When fully deployed the craft experienced over 9G of force as it slowed.

Here you can see Curiosity’s heat shield as it drops away from the rover during descent (click to enlarge) – Credit: NASA/JPL-Caltech

The image above was obtained by the Mars Descent Imager instrument (known as MARDI) and shows the 15-foot (4.5-meter) diameter heat shield when it was about 50 feet (16 meters) from the spacecraft.

It was obtained two and a half minutes before touchdown on the surface of Mars and about three seconds after heat shield separation.

Curiosity eyes up its main science target, Mount Sharp, which sits in the middle of the Gale Crater (click to enlarge) – Credit: NASA/JPL-Caltech

The rover’s shadow can be seen in the foreground above, and the dark bands beyond are dunes. Rising up in the distance is the peak of Mount Sharp (Aeolis Mons) at a height of about 3.4 miles, the base of which the Curiosity team will target as scientists believe it will hold clues to past environmental change.

The first colour image acquired from the surface by the Mars Hand Lens Imager (MAHLI) on the afternoon of the first day after landing (click to enlarge) – Credit: NASA/JPL-Caltech

In the distance, the image above shows the north wall and rim of the Gale Crater. The image is murky because the MAHLI’s removable dust cover is coated with dust blown onto the camera during the rover’s terminal descent.

Images taken without the dust cover in place are expected during checkout of the robotic arm in coming weeks (as the cover won’t be opened until around a week after landing).

Considering these images are the tip of what should become a very large iceberg, and Curiosity hasn’t yet properly woken up, there is so much promise and excitement surrounding Curiosity at the moment, and rightly so.

What fantastic times we live in :)

Source: NASA MSL

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NASA lands car-sized Curiosity rover on Mars – first images released

August 6, 2012

by yaska77

NASA has successfully landed the most advanced Mars rover ever built on the surface of the Red Planet.

The one-tonne, car-sized Curiosity, hanging by cables from a “sky crane” (rocket  backpack essentially) touched down earlier this morning ending a 36-week flight, and was greeted by cheers and hi-fives in the NASA control room monitoring the descent.

Artist’s concept shows how the “sky crane” slowly and precisely lowered Curiosity onto the surface of Mars – Credit: NASA/JPL-Caltech

The Mars Science Laboratory (MSL) spacecraft that carried Curiosity reportedly succeeded in every step of the most complex landing ever attempted on Mars, including the final severing of the bridle cords and flyaway maneuver of the rocket backpack.

One of the first images received from Curiosity after landing on Mars. You can see dust around the sides of the image kicked up during the landing (which will clear when the lens covers come off) – Credit: NASA/JPL-Caltech

NASA Administrator Charles Bolden said of the achievement “Today, the wheels of Curiosity have begun to blaze the trail for human footprints on Mars. Curiosity, the most sophisticated rover ever built, is now on the surface of the Red Planet, where it will seek to answer age-old questions about whether life ever existed on Mars – or if the planet can sustain life in the future.”

“This is an amazing achievement, made possible by a team of scientists and engineers from around the world and led by the extraordinary men and women of NASA and our Jet Propulsion Laboratory. President Obama has laid out a bold vision for sending humans to Mars in the mid-2030′s, and today’s landing marks a significant step toward achieving this goal.”

Another higher-res image from the rover (received a few hours after landing) shows more detail of the Martian surface, and one of the rear wheels of Curiosity – Credit: NASA/JPL-Caltech

Curiosity landed at 22:32 PDT on 5th August (05:32 UTC/06:32 BST on 6th August) near the foot of a mountain three miles tall and 96 miles in diameter inside Gale Crater. During its two-year primary mission, the rover will investigate whether the region ever offered conditions favorable for microbial life.

NASA will now be taking time to check all systems over the next few days (into weeks) before embarking on their primary mission.  We’ll be following developments closely and will share any new images as they’re released, with the first colour image of Curiosity’s surroundings expected in the next couple of days.

This is the fourth rover NASA has put on Mars, but the scale (and sophistication) of Curiosity dwarfs all previous projects.

You can watch the moment NASA received confirmation of success below via NASA TV Channel on YouTube.

You can read more detail about the Mars Science Laboratory and it’s fascinating mission here!

Source: NASA

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