Main Menu

Drop Down MenusCSS Drop 

Down MenuPure CSS Dropdown Menu
Showing posts with label SOLAR SYSTEM. Show all posts
Showing posts with label SOLAR SYSTEM. Show all posts

Wednesday 22 July 2015

See it! Moon, Venus, Jupiter, comet

Source: Earth Sky

What a glorious western twilight sky on the nights of July 17 and 18, 2015! Waxing moon, brightest planets, and Comet C/2014 Q1 (PANSTARRS).


Venus (top left), Jupiter and the moon made a triangle as seen from some parts of the world on July 18, 2015. Aimilianos Gkekas submitted this photo to EarthSky. He caught the trio from a monastery known as Meteora – literally ‘suspended in the sky’ – in Thessaly, Greece.


Moon, Venus, Jupiter and Comet C/2014 Q1 (PANSTARRS) on July 18 by John Lafferty. 


 Venus, Jupiter and the moon setting on July 18 as seen from Porto, Portual. The star above the planets is Regulus in the constellation Leo. Photo submitted by João Pedro Bessa.


Moon and Venus on July 18, 2015 by John Ashley in Kila, Montana. If you view larger, you can see both worlds are crescents as seen from Earth now. Read why Venus appears as a crescent now.


Moon and Venus on July 18, 2015 by Billie C. Barb at Mutiny Bay, Freeland, Washington. 


Another view of the moon and crescent Venus on July 18, this one in daylight, from Spencer Mann in Davis, California.


Thursday 16 July 2015

STUNNING FIRST HI-DEFINITION IMAGE OF PLUTO REVEALS HUGE MOUNTAINS


nh-plutosurface.0
The first ever high-resolution image of Pluto has been beamed back to Earth showing water ice and 11,000ft (3,350 metre) mountains. The mountains likely formed no more than 100 million years ago – mere youngsters relative to the 4.56-billion-year age of the solar system. Nasa says they may still be in the process of building
Like the rest of Pluto, this region would presumably have been pummeled by space debris for billions of years and would have once been heavily cratered – unless recent activity had given the region a facelift, erasing those pockmarks.
‘We now have an isolated small planet that is showing activity after 4.5 billion years,’ said Alan Stern, New Horizons’ principal investigator. ‘It’s going to send a lot of geophysicists back to the drawing board.’
‘This is one of the youngest surfaces we’ve ever seen in the solar system,’ added Jeff Moore of New Horizons’ Geology, Geophysics and Imaging Team (GGI).
This is the first time astronomers have seen a world that is mostly composed of ice that is not orbiting a planet.
Unlike the icy moons of giant planets, Pluto cannot be heated by the gravitational pull of a larger planetary body. Nasa says some other process must be generating the mountainous landscape.
‘This may cause us to rethink what powers geological activity on many other icy worlds,’ says GGI deputy team leader John Spencer of the Southwest Research Institute.
In a Wednesday press conference, scientists also revealed a high-resolution photo of Pluto’s moon Charon, which is covered in cliffs and ridges:
2A8FFC2200000578-3162894-image-m-5_1436991156346
They also released the first-ever photo of Pluto’s tiny moon Hydra, which appears to be covered in water ice:
nh-hydra_1.0
A new sneak-peak image of Hydra  is the first to reveal its apparent irregular shape and its size, estimated to be about 27 by 20 miles (43 by 33km). The surface shows differences in brightness, which suggests that Hydra’s outer layer is composed manly of water ice .
Read more: Daily Mail

Tuesday 14 July 2015

THE NEW HORIZONS PLUTO MISSION IS A BIG DEAL. HERE ARE SOME REASONS WHY


SOURCE : vox.com 
NASA’s New Horizons spacecraft is about to show us an alien world for the first time. At precisely 7:49 am ET on Tuesday, the probe will become the first spacecraft to fly by Pluto.
New Horizons has been en route for nine years, traveling more than 3 billion miles. The flyby will be over in a matter of minutes, as the probe frantically takes hundreds of photos and collects data on Pluto’s atmosphere, geology, and moons. All this data will be enormously valuable to scientists as they seek to understand our solar system and how it formed billions of years ago.
More than anything, this mission is about broadening our horizons — taking in just a little bit more of the impossibly vast universe we live in.

1) We’ve never seen Pluto before

Pluto feels familiar. It’s easy to imagine the small, frigid rock, millions of miles from the sun and covered in ice.
But what you’re picturing in your head when you think about Pluto is probably an artist’s illustration. Until very recently, we didn’t even know exactly what color it was — and the best photos we had of Pluto looked like this:
pluto-hubble
New Horizons is going to change that in a very big way. Already, as it’s closed in on Pluto, it’s given us way better photos than ever before:
Screen_Shot_2015-07-13_at_2.11.02_PM.0
Pluto (right) and its moon Charon, as seen by New Horizons on July 11. (NASA-JHUAPL-SWRI)
The high-resolution photos to come will give us detailed topographical maps, just like those provided by the satellites that orbit Earth. They could reveal mountains, ice caps, volcanoes, or even an ocean of liquid water under the ice. “Who knows what kind of bizarre things we’ll find up close?” Stern said.

2) This mission will remind you how vast space really is

Pale-Blue-Dot
Earth, as seen by the Voyager spacecraft, from more than 4 billion miles away.
We spend our entire lives on the surface of Earth — so it’s hard to really grasp how far away Pluto truly is from us.
But as an analogy, think of Earth as a basketball. By comparison, Pluto would be a little larger than a golf ball. But if you wanted to keep the scale constant, you’d have to put that golf ball incredibly far away: 50 to 80 miles (depending on its location in orbit). This mission, like many activities in space, is a good reminder of how vast our corner of the universe is — and how absurdly tiny our entire earthly realm of experience is by comparison.
And it’s not just the size of space that boggles the mind. It’s also the timescale on which everything occurs. Pluto takes 248 Earth years to orbit the sun. To put it another way, the entirety of US history has occurred during a single Plutonian orbit.

3) We won’t get many more missions like this for a while

europa
There’s a mission to Europa planned, but it won’t reach the moon for a decade or more.
The past few decades have been filled with all sorts of fascinating missions to the planets, moons, asteroids, and comets of our solar system — uncrewed probes sent every few years, run by trained scientists, and supported by government funding.
But the sad truth is that this era is largely drawing to a close. As David W. Brown writes in an article on the dark future of American space exploration, “There is nothing budgeted in the pipeline to take its place. Yesterday invested in today. But we are not investing in tomorrow.”
This is the result of cutbacks to NASA’s planetary exploration budget. The OSIRIS-REx probe will launch next year, to travel to an asteroid and bring back a sample, but it won’t return until 2023. Meanwhile, a mission to Jupiter’s moon Europa is in the works, but it likely won’t be launched until 2025 at the earliest, and wouldn’t reach Europa until the 2030s.
In other words: Enjoy this brief flyby. It’s going to be a while before any NASA probe visits a new world.

4)This is a staggering technological achievement

t’s hard to appreciate just how difficult it is to send a spacecraft to Pluto. But think of it this way: because it’s so incredibly far away, it took New Horizons nine years to cover the 3-billion-mile trip there — which means the craft is using decade-old technology, traveling a route that was calculated years ago.
Screen_Shot_2015-07-09_at_9.53.45_AM.0
New Horizons’ trajectory through the solar system.
Despite this, NASA engineers managed to get the tiny probe — about the size and shape of a grand piano — to an incredibly precise spot in space, using Jupiter’s gravity as a slingshot to accelerate it outward and a few thruster burns over the years to keep the probe on track.
Along the way, they had to worry about potentially damaging debris nearby Pluto — as well as a scary software glitch this past weekend, which was, thankfully, resolved. Now New Horizons is going to fly within 7,750 miles of Pluto, coming closer than its moons.
Because New Horizons is traveling at such a high speed (about 31,000 miles per hour) and can’t slow down, the flyby will be over in a matter of minutes — fording it to collect all its data in a tiny window of time.
And receiving all that data is another huge challenge. Because New Horizons is so far away, it takes about 4.5 hours for any data it sends back to reach Earth. And the signal is so faint that NASA has to use 200-foot-wide radio dishes (one each in Australia, California, and Spain) to pick it up. This means an extremely low rate of data transmission: about 1 kilobit per second, more than 50 times slower than a 56k modem from the ’90s. It takes more than 42 minutes for New Horizons to fully transmit an image that’s 1024 pixels wide.
If you haven’t been paying attention so far, now’s the time to start. This is a really big deal.

CHARON’S IMPACT CRATER EMERGES IN LATEST NEW HORIZONS SHOT


NASA/JHUAPL/SWRI

IN THE IMAGE NASA released of Charon yesterday, astronomers pointed out a collection of vaguely-defined features on the surface of Pluto’s biggest moon. Now, with this latest capture, the New Horizons team has confirmed that the big dent in the icy rock’s surface is in fact an impact crater, surrounded by a couple of deep canyons—one larger than Earth’s Grand Canyon.

Get ready for even more detailed images of Charon and its orbital buddy, Pluto, tomorrow morning when New Horizons makes its closest approach to the system. Geologists will be especially interested to take a closer look at the dark spot on the moon’s northern pole, and the rays of material you can see spraying out from the edges of the crater.

Source :Wired


Saturday 14 March 2015

Huge Saltwater Ocean Found on Jupiter Moon Ganymede

15-033i1

Artistic Impression of Ganymede (Largest Moon in the Solar System)

NASA has confirmed that Ganymede, one of the moons orbiting Jupiter, has a saltwater ocean lying below its icy exterior, making it a viable location for life to flourish.

The scientists studying the planet and its outlier moons through the Hubble Telescope shared the news in a statement Thursday, saying that the ocean may bear more liquid than all the water on Earth combined.

Ganymede is an anomaly among moons. It is the largest known moon in our solar system, and the only one that generates its own magnetic field. This attribute produces a phenomenon called aurorae—strips of radiant electrified gas that circle Ganymede’s poles. Because Ganymede is situated so close to its mother planet, any changes to Jupiter’s magnetic field directly affect that of its moon. So when Jupiter’s magnetic field shifts due to the planet’s rotation, Ganymede’s aurorae “rock” back and forth in a sort of cosmic mating dance.

Observing the interplay between the planet and its moon, scientists surmised that an ocean works against Jupiter’s magnetic pull, causing Ganymede to rock less violently than they had anticipated. Once they had observed the planet with the Hubble Telescope, the researchers built computer models that supported speculation that Ganymede has a salty ocean.


Researchers believe the subterranean ocean is 10 times as deep as Earth’s oceans.


Since water is necessary to sustain life, it’s possible that these oceans may confirm the long-suspected presence of life on other planets, or on moons such as Titan and Enceladus.


NASA has speculated since the 1970s that there was water on Ganymede. A 2002 Galileo mission confirmed that the moon had its own magnetic field, but the findings weren’t concrete enough to corroborate suspicion that Ganymede had a vast ocean beneath its outer crust—until now. In a statement, an assistant administrator of NASA’s Science Mission Directorate, John Grunseld, said, “A deep ocean under the icy crust of Ganymede opens up further exciting possibilities for life beyond Earth.”


Source:Newsweek.com

Friday 13 February 2015

[Video] Nasa revealed Far side of moon

back_side_of_the_moon_as16-3021-1

A number of people asked what the other side of the Moon looks like, the side that can't be seen from the Earth. This video answers that question. The imagery was created using Lunar Reconnaissance Orbiter data.

https://www.youtube.com/watch?v=cDHLdXu5JvI&feature=youtu.be

Source : NASA

Wednesday 11 February 2015

NASA spacecraft sends historic Pluto images

d2155b6e1064e6f001c91450a0c


NASA’s New Horizons spacecraft has sent its first stunning images of Pluto as the probe closes in on the dwarf planet.


pluto_jpg_2300753f


New Horizons was more than 203 million km away from Pluto when it began taking images, the US space agancy said in a statement.


Although still just a dot along with its largest moon, Charon, the images come on the 109th birthday of Clyde Tombaugh who discovered the distant icy world in 1930.


“My dad would be thrilled with New Horizons,” said Clyde Tombaugh’s daughter Annette Tombaugh, of Las Cruces, New Mexico.


“To actually see the planet that he had discovered, and find out more about it — to get to see the moons of Pluto — he would have been astounded. I am sure it would have meant so much to him if he were still alive today,” she added.


The new images, taken with New Horizons’ telescopic Long—Range Reconnaissance Imager (LORRI), are the first acquired during the spacecraft’s 2015 approach to the Pluto system which culminates with a close flyby of Pluto and its moons July 14.


Over the next few months, LORRI will take hundreds of pictures of Pluto, against a starry backdrop, to refine the team’s estimates of New Horizons’ distance to Pluto.


As in these first images, the Pluto system will resemble little more than bright dots in the camera’s view until late spring.


“Pluto is finally becoming more than just a pinpoint of light,” said Hal Weaver, New Horizons project scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.


“The dwarf planet will continue to grow larger and larger in the images as New Horizons spacecraft hurtles toward its targets. The new LORRI images also demonstrate that the camera’s performance is unchanged since it was launched more than nine years ago,” Weaver said.


Source: thehindu


Tuesday 27 January 2015

Scientists Discover Exoplanet With Rings Far More Impressive Than Our Saturn

J1407b

Artist’s conception of the extrasolar ring system circling the young giant planet or brown dwarf J1407b is shown. Credit: Ron Miller

Children and adults alike marvel at the rings around Saturn. In a model of our solar system, Saturn—and its rings—is typically the one that gets the most attention.

But while it is easy to be fascinated by Saturn, astronomers have recently found an exoplanet with an even grander expanse of wings that is sure to wow a new generation of stargazers.

“The star is much too far away to observe the rings directly, but we could make a detailed mode based on the rapid brightness variations in the star light passing through the ring system. If we could replace Saturn’s rings with the rings around J1407b, they would be easily visible at night and be many times larger than the full moon,” explains lead researcher Matthew Kenworthy. “The details that we see in the light curve are incredible. The eclipse lasted for several weeks, but you see rapid changes on time scales of tens of minutes as a result of fine structures in the rings.”

Study co-author Eric Mamaek, who first found the rings of the planet, comments, “The planetary science community has theorized for decades that planets like Jupiter and Saturn would have had, at an early stage, disks around them that then led to the formation of satellites. However, until we discovered this object in 2012, no-one had seen such a ring system. This is the first snapshot of satellite formation on million-kilometer scales around a substellar object.”

The University of Rochester professor of physics and astronomy goes on to say, “This planet is much larger than Jupiter or Saturn, and its ring system is roughly 200 times larger than Saturn’s rings are today. You could think of it as a kind of super Saturn.”

Source : piercepioneer.com

Sunday 25 January 2015

NASA unveils 100-millionth picture of the sun

10948933_770503933005593_281558100_n

An instrument onboard the Solar Dynamics Observatory captured NASA's 100-millionth image of the sun. Four telescopes work parallel to capture eight images of the sun and cycle through 10 different wavelengths every 12 seconds.

A National Aeronautics and Space Administration instrument aboard a sun-viewing spacecraft has captured its 100-millionth image of the sun.

The instrument, on the Solar Dynamics Observatory, is the Atmospheric Imaging Assembly and uses four telescopes. The photo was taken Jan.19, according to NASA.

https://www.youtube.com/watch?v=7VVxdN79QZY

In the nearly five years since its start in 2010, Solar Dynamics Observatory has captured images of the sun "to help scientists better understand how the roiling corona gets to temperatures some 1,000 times hotter than the sun's surface, what causes giant eruptions such as solar flares, and why the sun's magnetic fields are constantly on the move," NASA says.

Source : USA TODAY

Sunday 18 January 2015

Researchers: Solar system may have Planet X , Planet Y

planet-surface-18356-1920x1080

The presence of two additional planets might explain the unexpected orbital features of some trans-Neptunian objects.

Scientists have postulated the existence of possibly two undiscovered planets beyond the orbit of Neptune to explain discrepancies in the orbits of extreme trans-Neptunian objects (ETNO). The objects have orbits that take them beyond the orbit of the planet Neptune.

Theory predicts that they be randomly distributed and that their orbits must have a semi-major axis with a value around 150 AU; an orbital inclination of nearly zero degrees; and an angle of perihelion, the point in the object’s orbit at which it is closest to the Sun, of zero to 180 degrees.

However, a dozen ETNO do not fit these orbital criteria. These objects have semi-major axis values of 150 to 525 AU, orbital inclinations of around 20 degrees, and angles of perihelion far from 180 degrees.

According to a statement, a new study by astrophysicists at the Complutense University of Madrid (UCM) and University of Cambridge have calculated that these orbital discrepancies could be explained by the existence of at least two additional planets beyond the orbits of Neptune and dwarf planet Pluto. Their study suggests that the gravitational pulls of those two planets must be disturbing the orbits of some smaller ETNO.

However, there are two difficulties with the hypothesis. One is that current models of the formation of our solar system do not allow for additional planets beyond Neptune. Secondly, the team’s sample size is very small, only 13 objects. However, additional results are in the pipeline, which will expand the sample.

“This excess of objects with unexpected orbital parameters makes us believe that some invisible forces are altering the distribution of the orbital elements of the ETNO and we consider that the most probable explanation is that other unknown planets exist beyond Neptune and Pluto,” said Carlos de la Fuente Marcos of UCM and lead author on the study.

The new findings have been published in two papers published in the journal Monthly Notices of the Royal Astronomical Society Letters.

Source : thespacereporter

Thursday 13 November 2014

The Rosetta comet landing has made history

http://i.telegraph.co.uk/multimedia/archive/02758/Rosetta_2758749b.jpg

After 10 years of hard work and one nerve-wracking night, the Rosetta mission has made history by landing on the surface of a comet.

The lander Philae was confirmed to touch down on the surface of the comet more than 300 million miles away at 11:03 a.m. Eastern. Now, scientists expect it to send a panoramic image home and begin analyzing the comet for scientists back on Earth.

Philae is already transmitting scientific data back home, but we're still waiting to see whether the probe is in a stable position. Until we know it's anchored tight, it could roll onto its back and never get back up.

Tensions were high in the European Space Agency's German mission control center, especially as the landing window approached. Because the comet that Philae landed on is so far from Earth, there's a communications delay of 28 minutes. So as the minutes ticked by, the Rosetta team knew that Philae had already either landed or failed — and there was nothing they could do but wait for the data to reach them. Those following the video online were nearly as desperate for news, and Twitter became a sounding chamber of anticipation and excitement.

But a few minutes after 11 a.m., the stern, cautious expressions of the mission control team melted into smiles. And just like that, the world swiveled from anxiety to elation: Philae was on the surface of the comet and ready to do some science.

The comet contains the materials that originally formed our solar system, frozen in time. By digging them out, we can learn more about the origins of our planet. The Rosetta spacecraft has made invaluable observations about the comet's attributes, and it will continue to do so as it follows it around the sun for the next year. But Philae will be able to look more closely at the comet's physical and molecular composition.

"It's a look at the basic building blocks of our solar system, the ancient materials from which life emerged," said Kathrin Altwegg of the University of Bern in Switzerland, one of the Rosetta project's lead researchers. "It's like doing archaeology, but instead of going back 1,000 years, we can go back 4.6 billion."

It's no easy thing to land on a comet's surface: These chunks of rock and ice are constantly spinning, and Comet 67P/Churyumov-Gerasimenko, which was discovered in 1969, orbits the sun at a speed of about 85,000 mph. It's irregularly shaped — like a toddler's play-dough impression of a duck, or something — and its surface is uneven and pitted. And in a universe of unimaginable proportion, Rosetta's target is just 2.5 miles in diameter — smaller than Northwest Washington's Columbia Heights neighborhood.

So Rosetta has taken an onerous journey to get in sync with the comet's orbit, which would allow it to drop down a lander. In 2004, the spacecraft began what would be three looping orbits around the sun, altering its trajectory as it skimmed Mars, just 150 miles from the surface, and enduring 24 minutes in the planet’s shadow to align with Churyumov-Gerasimenko. The cumulative distance traveled by the craft – with all its looping and gravity assists – is a stunning 4 billion miles. “When the Rosetta signal reappeared after the passage behind Mars, shortly after the end of the ‘shadow’ period, there was a collective sigh of relief,” ESA said.

At one point in 2011, the spacecraft even had to hibernate for nearly three years. It flew so far from the sun — nearly 500 million miles — that its solar panels couldn't leech enough energy to keep the spacecraft operational. But in January of this year, Rosetta woke up, and quickly approached its target.

The last leg of this landing has not been without its bumps. Even as the mission approached its most critical moment, controllers at the European Space Agency on Tuesday night reported a problem with the thruster on the lander that could make for a rough landing. The gravity of the problem — and the extent to which it threatened the mission — remained unknown. “We’ll need some luck not to land on a boulder or a steep slope,” blogged Stephan Ulamec, lander manager for the project.

Source : washington post

Sunday 9 November 2014

Amazing photo of Saturn and its Titan moon looks like high art in deep space

Follow us on Google+ , Twitter and Facebook

PIA18291

This amazing image shows Saturn and its moon Titan as crescents on Aug. 11, 2013. NASA/JPL-CALTECH/SPACE SCIENCE INSTITUTE

An amazing photo taken by a NASA probe shows Saturn and its large moon Titan shining as pretty crescents in deep space.

The two cosmic bodies were imaged by the Cassini spacecraft, which has been exploring the Saturn system for about 10 years. The image -- released on Monday (Nov. 3) -- was captured as the robotic ship was flying about 1.1 million miles (1.7 million kilometers) from the ringed wonder on Aug. 11, 2013, according to NASA. Some of Saturn's ring plane can even be seen in the black and white image.

"More than just pretty pictures, high-phase observations -- taken looking generally toward the sun, as in this image -- are very powerful scientifically since the way atmospheres and rings transmit sunlight is often diagnostic of compositions and physical states," NASA officials said in an image description. "In this example, Titan's crescent nearly encircles its disk due to the small haze particles high in its atmosphere scattering the incoming light of the distant sun."

Tuesday 4 November 2014

NASA rocket to click 1,500 images of Sun in 5 minutes

Follow us on Google+ , Twitter and Facebook


VBK-03-SOLAR_FLARE_2184508f

This image provided by NASA shows the sun emitting a significant X3.2-class flare erupting from the lower half of the sun, peaking at 5:40 p.m. EDT on Oct. 24, 2014. NASA's Solar Dynamics Observatory, which watches the sun constantly and captured images of the event.

A sounding rocket fitted with technology to gather 1,500 images of the Sun in flat five minutes is set for launch on Monday.


Capturing five images per second, the Rapid Acquisition Imaging Spectrograph Experiment (RAISE) mission will focus in on the split-second changes that occur near active regions on the Sun.


These are areas of intense and complex magnetic fields that can give birth to giant eruptions on the Sun that shoot energy and particles out in all directions, the U.S. space agency said in a statement.


“Even on a five-minute flight, there are niche areas of science we can focus on well. There are areas of the Sun that need to be examined with the high-cadence observations we can provide,” said Don Hassler, solar scientist at the Southwest Research Institute in Boulder, Colorado.


RAISE will create a kind of data product called a spectrogram which separates the light from the sun into different wavelengths.


“The Sun has been extremely active recently, producing several X-class flares in the past few weeks. The team will aim their instrument at one of these active regions to try to understand better the dynamics that cause these regions to erupt,” Mr. Hassler explained.


The team hopes to see how heat and energy move through such active regions, which, in turn, helps scientist understand what creates the regions and perhaps even what catalyses the sun’s eruptions.


RAISE’s launch time is planned for 2.07 p.m. (EST) from the White Sands Missile Range near Las Cruces, New Mexico.

Saturday 1 November 2014

Cassini sees sunny seas on Titan

pia18432-16

This near-infrared, color view from Cassini shows the Sun glinting off of Titan's north polar seas.

As it soared past Saturn’s large moon Titan recently, NASA’s Cassini spacecraft caught a glimpse of bright sunlight reflecting off hydrocarbon seas.

In the past, Cassini had captured separate views of the polar seas and the Sun glinting off them, but this is the first time both have been seen together in the same view.

Also in the image:

– An arrow-shaped complex of bright methane clouds hovers near Titan’s north pole. The clouds could be actively refilling the lakes with rainfall.

– A “bathtub ring,” or bright margin, around Kraken Mare — the sea containing the reflected sunglint — indicates that the sea was larger at some point, but evaporation has decreased its size.

Titan’s seas are mostly liquid methane and ethane. Before Cassini’s arrival at Saturn, scientists suspected that Titan might have bodies of open liquid on its surface. Cassini found only great fields of sand dunes near the equator and lower latitudes but located lakes and seas near the poles, particularly in the north.

The new view shows Titan in infrared light. It was obtained by Cassini’s Visible and Infrared Mapping Spectrometer (VIMS) on August 21.

 

Folow us on Google + Dark Matter Space

Friday 31 October 2014

Jupiter's ‘one-eyed giant Cyclops’ captured by Hubble

tumblr_ne846v5cjt1r7n7vio1_500

A stunning event captured by NASA’s Hubble Telescope shows a big black eye staring back from Jupiter's Great Red Spot storm. In reality, it is shadow play on a planetary scale.

The image was captured by NASA’s Hubble Space Telescope as it tracked changes in Jupiter’s immense Great Red Spot storm – a storm that has been raging for over 300 years. The black eye is caused by the shadow of the Jovian moon, Ganymede, sweeping across the center of the storm.

“For a moment, Jupiter stared back at Hubble like a one-eyed giant Cyclops,”
a NASA spokesman told the Daily Express.

The Great Red Spot, the largest known vortex in the Solar System at 10,000 miles wide, is a persistent anti-cyclonic storm just south of Jupiter's equator. It has been raging for between 300 and 400 years, blowing winds at 345 miles an hour – speeds that are beyond comparison with even an Earthly Category 5 hurricane, which can only maximize up to 200 miles.

Astronomers are only beginning to fully understand the complexity of Jupiter, a gas giant which has a mass 317 times bigger than Earth. The planet has 62 moons – including four large ones called the Galilean moons, first discovered by Galileo Galilei in 1610. Ganymede is the largest of these moons.

Saturday 25 October 2014

Hubble captures stunning image of a comet's brush past Mars

comet_springs_0

NASA has just released this image of comet Siding Spring's close brush past Mars, and it is thrilling.

The image you see above -- a fuzzy white comet hovering above a glowing rust-colored planet -- is actually a composite of several images taken by the Hubble Space Telescope on Saturday and Sunday.

NASA's Hi Res camera aboard a Mars orbiter captured the first images of the nucleus of a comet
There are a few reasons that Hubble could not take a picture like this in a single shot. For one, Mars is 10,000 times brighter than its cometary visitor, making it impossible to see details of Siding Spring and Mars in one exposure.

Also, the two objects were racing past each other during their near-rendezvous on Sunday. At least one of the objects would have been blurry if Hubble tried to take an image of them simultaneously.

The starfield that the two bodies are set against was provided by the Palomar Digital Sky Survey.

Despite being a bit of a cut and paste job, NASA officials say the image accurately illustrates the distance between Siding Spring and Mars at the time of the comet's closest approach.

It also accurately represents the relative sizes of the two bodies.

Saturday 5 October 2013

Scientists develop new theory about how life forms on asteroids

 

pic_asteroids_1

 

Scientists have a working theory on how life may have come to Earth via an asteroid. But how did life get onto an asteroid in the first place? Several theories exist, but they're all a little bit different. Scientists at Rensselaer Polytechnic Institute, however, have come up with a new theory that could properly explain how organic material forms on an asteroid.

The theories most often taught in astrobiology revolve around the idea that the asteroids were once warm enough that they could sustain liquid water, which is necessary for organic molecules to form. The space where they originated in is cold, so how did they get heated up to the right temperature? One theory states that the asteroids were heated radioactively, similar to Earth’s interior. The other popular theory involves how plasma interacts with a magnetic field. However, both of these theories are based on the assumption that the asteroid belt between Jupiter and Mars was once warm enough to do do this. Unfortunately, these theories don’t work because the sun was much dimmer back then than originally thought, meaning that the area was even colder than it is now.

The Rensselaer scientists started by looking at the theory involving magnetic fields. That theory states that an asteroid creates an electric field when it moves through a magnetic field. This heats up the asteroid. This theory makes the assumption that a strong solar wind was present, but that has been disproved.

However, starting with this theory gave them something to work with. They used a new understanding of how the process works, and re-calculated the electric field. With that, they determined that something called multi-fluid magneto-hydrodynamics was also at work on the asteroids. This regards how plasma interacts when introduced to a magnetic field. Generally speaking, the plasma’s neutral particles rub up against other particles and create friction. This friction creates heat. This heat creates the correct temperature for organic molecules to form.

Although the scientists feel that this theory is a good one, they still believe there are more questions to be asked and answered regarding the origin of life on asteroids.

Wednesday 2 October 2013

Did Venus give Earth the moon?

 

 

VenusMoonEarth_m_1001

 

 

LONDON —The Earth's moon may be a present from Venus, which once had a moon and then lost it, a new theory suggests. Under the theory, Earth's gravity captured Venus' old moon, giving our planet its big natural satellite.

This idea contrasts to the thinking of the vast majority of moon researchers, who believe that the Earth's moon formed some 4.5 billion years ago when a planet-size body slammed into nascent Earth at high speed.

This giant impact hypothesis, however, has its own issues, as did all the alternative moon formation theories discussed this week at the Origin of the Moon conference at the Royal Society here. [The Moon: 10 Surprising Lunar Facts]

"I think part of the key to [understanding] the moon may be that Venus has no moon, and we certainly have to study it (Venus) more," said Dave Stevenson, professor of planetary science at the California Institute of Technology, who proposed the Venus idea at the conference. In an interview with SPACE.com after his presentation, Stevenson said that he himself favored the impact theory on moon formation, but unfortunately this theory did not yet answer all the questions.

How did Earth get its moon?
The "moon capture" theory assumes that Earth used its gravitational pull to attract a pre-formed space body into its orbit, thus making a satellite of this object. [How the Moon Formed: A Lunar Tour (Video)]

However, the geochemical composition of the moon and Earth likely trips up this theory. Analyses of the lunar rocks brought back by NASA's Apollo moon landing missions have shown that the satellite has an isotopic composition very similar to that of Earth.

Isotopes refer to varieties of chemical elements that have the same number of protons, but different numbers of neutrons. Two isotopes behave the same chemically.

And if both moon and Earth have very similar isotopes, it makes the capture theory difficult to maintain, said Alex Halliday, head of science at Oxford University. Such isotopic similarities suggest that "the material that makes up the moon did actually either come out of the Earth, or that the stuff that was in the disk that formed the moon got completely mixed up with the stuff in the Earth."

Nonetheless, some aspects of the idea that the moon may have come from Venus are intriguing, he said.

"The reason why it's interesting is that Earth and Venus are close to each other. They have similar mass, and people think they have probably formed in a similar way," he said. "So the question is, if Earth and Venus formed in similar ways, how come the Earth has a moon and Venus doesn't?"

Stevenson's idea would answer that question, Halliday said, "throwing a new twist into the whole capture theory."

There are many theories for what might have caused such a large moon for a planet as small as Earth. The most popular theory assumes an impact, where the debris of the collision — a mix of the material from Earth and the other body — gave birth to the moon. This body then stayed in orbit about the Earth, forever bound to its new home.

Another posits that the moon "fissioned" from the Earth's crust and mantle due to the centrifugal force of a rapidly spinning early Earth.

Another theory, called binary accretion, assumes that the moon was born at the same time and place as Earth.

MoonFormation_m_1001

 

 

Wandering moons
The biggest flaw of the fission, capture and binary accretion theories is that they cannot account for the high angular momentum of the Earth-moon system.

Scientists believe that initially the Earth was spinning so rapidly that a day lasted only five or six hours, and the moon was in a very low-altitude orbit. But gradually, tidal drag slowed the Earth's spin and pushed the moon's orbit up to its present level.

The capture theory will always face a challenge explaining the similar composition of the moon and Earth, Stevenson said. But if scientists analyze rocks from Venus and they turn out to be very similar to those on Earth, that would argue in favor of the capture theory. The giant impact idea also has trouble explaining why the Earth and the moon are so peculiarly similar.

Even though he himself favors the impact theory, Stevenson said he picked Venus for a larger purpose.

"We cannot understand the terrestrial planets unless we understand Venus, and at the moment, we don't know anything about Venus in terms of the isotopes" it has, he says. "And I also think that as a test of our understanding of the origin of the moon, we need to understand whether Venus ever had a moon."

If Venus indeed once had a moon and lost it, how might the planet have acquired a satellite in the first place?

Unlike what would have happened with Earth, the formation of any moon of Venus may have occurred much earlier, shortly after the formation of the solar system, Stevenson said.

Back then, there were still a lot of things whizzing around," he said.

So Venus possibly would have gotten its moon after an even earlier giant impact of some sort, and the planet may have lost its moon either by collision or by escape. This would mean an object passed close by the Venus system and caused the moon to depart from its orbit, says Stevenson.

But even aside from the Venus idea, the widely preferred giant impact theory still "is not satisfactory in all respects," Stevenson said.

Sean Solomon, the director of the Lamont-Doherty Earth Observatory of Columbia University, agrees. "We are still on the trail of the detailed scenario that would seem both likely and complete in its ability to account for all the geochemical and geophysical observations," he said.

Until scientists have figured out that scenario, even the escaped moon of Venus is a plausible theory, he said.

"Even with the giant impact idea, we don't know the origin of the impacting object. It could've been an early protoplanet. It could've been a moon of another object that was removed from the gravitational field of its original [planet]. It could've been a very large asteroid. All of those scenarios are still open."