Tag: Hubble space telescope

News from Space: Jupiter’s Eye Disappearing

jupiterJupiter’s Red Eye, that trademark spot on the gas giant’s surface that is its most recognizable feature, appears to be shrinking faster than ever. Earlier this year, amateur astronomers had observed and photographed the Eye and noted that it had grown smaller. Shorlty thereafter, astronomers observed it using the Hubble Space Telescope and came to the same conclusion. Based on their calculations, they estimate that Jupiter’s Eye, a giant long-lasting storm, is narrowing by more than 900 kilometres a year, much faster than before.

At this rate, they claim, it will be gone by 2031 – just 17 years from now. Using historic sketches and photos from the late 1800s, astronomers determined the spot’s diameter then at 41,000 km (25,475 miles) across. Now, it is turned from a giant ovoid into a discrete circle that is a mere 16,500 kilometres (10,252 miles) across. Many who’ve attempted to see Jupiter’s signature feature have been frustrated in recent years not only because the spot’s pale color makes it hard to see  against adjacent cloud features, but because it’s physically getting smaller.

Jupiter-GRS-Hubble-shrink-panel-580x399As to what causing the drastic downsizing, there are no firm answers yet. However, NASA has a theory, which was shared by Amy Simon of NASA’s Goddard Space Flight Center in Maryland, USA:

In our new observations it is apparent that very small eddies are feeding into the storm. We hypothesized that these may be responsible for the accelerated change by altering the internal dynamics of the Great Red Spot.

Michael Wong, a scientist at the University of California, Berkeley, seems to be in agreement. He stated that one theory is the spot eats smaller storms, and that it is consuming fewer of them. But for the time being, scientists can’t be sure why its getting smaller, why the eye is red in the first place, or what will happen once it is completely gone.

Jupiters_EyeThe Great Red Spot has been a trademark of the planet for at least 400 years – a giant hurricane-like storm whirling in the planet’s upper cloud tops with a period of 6 days. But as it’s shrunk, its period has likewise grown shorter and now clocks in at about 4 days. The storm appears to be conserving angular momentum by spinning faster and wind speeds are increasing as well, making one wonder whether they’ll ultimately shrink the spot further or bring about its rejuvenation.

In short, the eye could become a thing of the past, the sort of thing children many years from now will only read about or see in pictures to give them some idea of how the Solar System once looked. Or, its possible that it could blow up again and become as it once was, a massive red Eye observable from millions of kilometres away. Who knows? In the meantime, check out this video by NASAJuno, explaining what little we know about Jupiter’s most prominent feature (while it lasts):

Happy Birthday Hubble!

hubble_in_orbit1Last month, the Hubble Space Telescope celebrated its 24th birthday. And in honor of this occasion, NASA has released a video entitled “Evaporating Peaks – Pillars in the Monkey Head Nebula”. This video, which showcases visible and infrared light views of a collection of pillars along one edge of the Monkey Head Nebula (also known as NGC 2174) is just the latest in series of simulations that attempt to recreate what it would be like to step into a major stellar body.

Like all nebulas, NGC 2174 is a star-forming region in which bright, newborn stars near the center of the nebula illuminate the surrounding gas, creating the brilliant images we see in the video. The radiation from these stars, combined with strong stellar winds, also erode areas of lower density gases, which in turn causes pockets of higher density gas to turn into visible formations. This is what leads to the creation of the pillars and peaks of gas that run along the inner edge of this roughly circular cloud.

The sequence begins with a view of the night sky near the constellation of Gemini and Orion and then zooms through observations from the Digitized Sky Survey 2 to reveal a Hubble Space Telescope visible light view of the top of this region of pillars.


Sources: universetoday.com, hubblesite.org

News From Space: 200 km Water Jets on Europa

europa-landerAs the prime candidate for extra-terrestrial life, the Jovian moon of Europa has been the subject of much speculation and interest over years. And while our understanding of the surface has improved – thanks to observations made by several space probes and the Hubble space telescope – what lies beneath remains a mystery. Luckily, Europa may yet provide Earth scientists with a chance to look at its interior.

Earlier this month, data collected from the Hubble space telescope suggested that enormous jets of water more than 200 kilometers tall may be spurting intermittently from the moon’s surface. The findings, presented last week to the American Geophysical Union, await independent confirmation. But if the jets are real, the frozen world would join the tiny number of others known to have active jets, including Saturn’s moon Enceladus and Neptune’s moon Triton.

europa-lander-2What’s more, should these newly observed water plumes be tapping into some Europan sea, they could be bringing material to the surface that would otherwise stay hidden. Follow-up observations from Earth or with probes around Europa could sample the fountains, hunting for organic material and perhaps finding the evidence need to prove that living organisms exist beyond Earth.

Scientists spotted the plumes thanks to ultraviolet images taken by Hubble in December 2012. The research team, which hails from the Southwest Research Institute in Texas, then published their research in Science magazine. In the paper, astronomer and co-author Lorenz Roth explained their findings:

We found that there’s one blob of emission at Europa’s south pole. It was always there over the 7 hours we observed and always at the same location.

Previous observations from NASA’s Galileo mission, which visited the Jupiter system in the 1990s and early 2000s, suggest that Europa’s south pole is full of ridges and cracks quite similar to features called tiger stripes on Enceladus that spew water.

europa_chaosterrainLorenz and his team looked back through previous Hubble data to see if the plumes could have been spotted earlier but saw nothing, suggesting that they are likely transient. At the time, Europa was at its farthest from Jupiter, which could explain why the jets appeared only then. Researchers recently determined that Enceladus’ plumes are weakest when the moon is closest to Saturn, likely because the ringed planet’s gravity squeezes the tiger stripes shut.

Astronomer Kurt Retherford, also of SwRI and another co-author, claimed that the case of Enceladus helped them to make a connection with what they were observing:

We actually saw this press release on Enceladus. And we thought, ‘Oh my god! This is the explanation’” for why Europa’s plumes might only appear when it’s far from Jupiter.

In the past, scientists have looked for evidence of jets coming from Europa’s surface. When the Voyager probes flew by in the 70s, one image showed a fuzzy spot that some thought to be a plume, though most considered it an artifact of imaging. Galileo also saw a row of dark spots on a ridge of Europa which looked similar to spots seen on planet Earth before an eruption begins.

europaBecause of these previous false positives though, scientists are likely to be cautious when interpreting these newest results. But even with these reservations, Robert Pappalardo – who leads the planning team for the Europa Clipper Pre-Project (a proposed mission to Europa) – said that he’s already discussing with other scientists how these new results should affect their study priorities.

For instance, some future orbiter headed to Europa could carry detectors specifically designed to search for heavy organic molecules that could be indicative of life in the subsurface. When it passed over the geyser’s spray, it would be bathed in material from the moon’s interior, giving scientists a window into Europa’s ocean. Pappalardo also hopes that the finding will help push Europa to a place of high priority in NASA’s exploration agenda.

Due to budget constraints, a manned mission is not yet feasible, but NASA has indicated that it would be willing to send a robot lander there in the near future. In addition, recent computer models provided from the University of Texas showed that the ice is likely to be thinnest at the equator. Between the possibility that the oceans might be most accessible in this region, and the likelihood that some of that water escapes into space, unlocking the mysteries of the Jovian satellite might be easier than previously thought.

europa_gieserSources: wired.com, science.jpl.nasa.gov

Alien Spotting by 2020?

alien-worldWith recent observations made possible by the Kepler space telescope, numerous planets have been discovered orbiting distant stars. Whereas previous observations and techniques could detect exoplanets, scientists are now able to observe and classify them, with the ultimate aim of determining how Earth-like they are and whether or not they can support life.

Combined with advanced astronomical techniques, the latest estimates claim that there may be are up to 50 sextillion potentially habitable planets in the universe. With their eyes on the next step, the scientific community is now preparing to launch a bevy of new space telescopes that can peer across the universe and tell us how many of those planets actually harbor life.

TESSOne such telescope is NASA’s Transiting Exoplanet Survey Satellite (TESS), which will launch in 2017. While Kepler was focused on a single patch of sky with around 145,000 stars, TESS will be equipped with four telescopes that keep track of around 500,000 stars, including the 1,000 nearest red dwarfs. TESS is expected to find thousands of orbiting, Earth-sized-or-larger planets around these stars.

But to find out whether or not any of those planets actually house life, another sophisticated telescope needs to be employed – the James Webb Space Telescope.Whereas TESS is Kepler’s successor, the James Webb Space Telescope – a joint NASA/ESA/CSA venture – is the planned successor for the Hubble Telescope and is due to launch in 2018.

TESS_Space_Telescope_Mirror37-640x425The JWST has a primary mirror that’s about five times larger than Hubble’s (pictured above), which means it can resolve much fainter signals, locating stars and other objects that have never been seen before. Because it primarily operates in the infrared band (whereas Hubble was tuned towards visible light), the JWST will also be able to see through dust clouds into hidden areas of space.

The JWST’s scientific payload includes a spectrometer that’s sensitive enough to analyze the atmosphere of distant planets. By measuring light from the parent stars, and how its reflected in the planets atmospheres, it will be able to determine if there are life-supporting elements and evidence of biological life – such as oxygen and methane.

TESS_comparisonBecause these planets are light years away, and because the reflected light is incredibly dim, the James Webb Space Telescope will only be able to do this for large planets that orbit red and white dwarfs. Still, that leaves thousands or even millions of candidates that it will be able to observe, and determine whether or not they are already inhabited by extra-terrestrial life.

And last, but not least, there’s the New Worlds Mission, which aims to put a Starshade – which is essentially a big flying space umbrella – into space. This disc would then fly between the James Webb Space Telescope and the star its observing, blocking out large amounts of light and the result “noise pollution” from nearby bright stars that the JWST isn’t observing.

Starshade_1280x720_H264With the Starshade in place, the JWST would be able to probe thousands of nearby planets for signs of life and return data to Earth that is of far greater accuracy. The New Worlds Mission is currently in the prototyping stage, but NASA hopes to procure the necessary funding by 2015 and and launch it within the JWST’s own lifetime.

Because of all this, it is now believed that by 2020 (give or take a few years) we will have the ability to directly image a distant planet and analyze its atmosphere. And if we find methane or another biological marker on just one planet, it will completely redefine our understanding of the universe and the lifeforms that inhabit it.

The answer to the question – “are we alone in the universe?” – may finally be answered, and within our own lifetime. And in the meantime, be sure to enjoy this video of the Starshade space umbrella, courtesy of New Scientist.


Sources: extremetech.com, wired.co.uk, newscientist.com