Science is the poetry of Nature.







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Posts tagged "solar system"

humanoidhistory:

The planet Saturn, February 2014, observed by the Cassini space probe.

(NASA Jet Propulsion Laboratory)

humanoidhistory:

Concept art of a cozy 3D-printed moon base, courtesy of the European Space Agency.

(via kenobi-wan-obi)

humanoidhistory:

The Mare Orientale basin on the Moon, observed in a flyover by NASA’s GRAIL space probe, April 2012.

humanoidhistory:

The Mare Orientale basin on the Moon, observed in a flyover by NASA’s GRAIL space probe, April 2012.

(via kenobi-wan-obi)

gunsandposes:

Our globe spins away, sourced from a Google Earth-inspired video posted by Ed Parsons, a “Geospatial Technologist” for Google.

gunsandposes:

Our globe spins away, sourced from a Google Earth-inspired video posted by Ed Parsons, a “Geospatial Technologist” for Google.

(via humanoidhistory)

heythereuniverse:

Double-Star Systems Can Be Dangerous for Exoplanets | Space.com

Alien planets born in widely separated two-star systems face a grave danger of being booted into interstellar space, a new study suggests.

Exoplanets circling a star with a far-flung stellar companion — worlds that are part of “wide binary” systems — are susceptible to violent and dramatic orbital disruptions, including outright ejection, the study found.

Such effects are generally limited to sprawling planetary systems with at least one distantly orbiting world, while more compact systems are relatively immune. This finding, which observational evidence supports, should help astronomers better understand the structure and evolution of alien solar systems across the galaxy, researchers said.

[Read more]

ikenbot:

HiRISE Updates: Fresh New Batch of Gorgeous Geological Art from Mars

1. Stunning Landscape Near Mamers Valles: This region of Mars has been long studied for its evidence of glacial-like flow features. The landscape is dominated by flat top mesas and flat valley floors. But a closer look shows evidence that soil material is flowing ever so gradually from the edges of the mesas out into the valleys.

2. Layers in Northeast Sinus Meridiani: The objective of this image is to examine the exposure of thin layers along the walls of a few-kilometer-wide valley in Sinus Meridiani.

3. Martian Mélange: “Mélange” means a confusing mixture, and is used to describe rocks scraped off the top of a downward-moving tectonic plate in a subduction zone on Earth. On Mars it is probably mostly impact cratering that creates such chaotic mixture of rock types rather than plate tectonics.

ikenbot:

Jupiter’s Spots

In what’s beginning to look like a case of planetary measles, a third red spot has appeared alongside its cousins — the Great Red Spot and Red Spot Jr. — in the turbulent Jovian atmosphere.

This third red spot, which is a fraction of the size of the two other features, lies to the west of the Great Red Spot in the same latitude band of clouds.

The new red spot was previously a white oval-shaped storm. The change to a red color indicates its swirling storm clouds are rising to heights like the clouds of the Great Red Spot. One possible explanation is that the red storm is so powerful it dredges material from deep beneath Jupiter’s cloud tops and lifts it to higher altitudes where solar ultraviolet radiation — via some unknown chemical reaction — produces the familiar brick color.

Detailed analysis of the visible-light images taken by Hubble’s Wide Field Planetary Camera 2 on May 9 and 10, and near-infrared adaptive optics images taken by the W.M. Keck telescope on May 11, is revealing the relative altitudes of the cloud tops of the three red ovals. Because all three oval storms are bright in near-infrared light, they must be towering above the methane in Jupiter’s atmosphere, which absorbs the Sun’s infrared light and so looks dark in infrared images.

Turbulence and storms first observed on Jupiter more than two years ago are still raging, as revealed in the latest pictures. The Hubble and Keck images also reveal the change from a rather bland, quiescent band surrounding the Great Red Spot just over a year ago to one of incredible turbulence on both sides of the spot.

Red Spot Jr. appeared in spring of 2006. The Great Red Spot has persisted for as long as 200 to 350 years, based on early telescopic observations. If the new red spot and the Great Red Spot continue on their courses, they will encounter each other in August, and the small oval will either be absorbed or repelled from the Great Red Spot. Red Spot Jr. which lies between the two other spots, and is at a lower latitude, will pass the Great Red Spot in June.

Full Photo Description

(via kenobi-wan-obi)

expose-the-light:

Most Powerful Storms of the Solar System

ikenbot:

Phobos: Doomed Moon of Mars

This moon is doomed. Mars, the red planet named for the Roman god of war, has two tiny moons, Phobos and Deimos, whose names are derived from the Greek for Fear and Panic.

These martian moons may well be captured asteroids originating in the main asteroid belt between Mars and Jupiter or perhaps from even more distant reaches of the Solar System. The larger moon, Phobos, is indeed seen to be a cratered, asteroid-like object in this stunning color image from the Mars Reconnaissance Orbiter, recorded at a resolution of about seven meters per pixel.

But Phobos orbits so close to Mars - about 5,800 kilometers above the surface compared to 400,000 kilometers for our Moon - that gravitational tidal forces are dragging it down. In 100 million years or so Phobos will likely be shattered by stress caused by the relentless tidal forces, the debris forming a decaying ring around Mars.

expose-the-light:

Most Spectacular Shots From 50 Years of Robotic Solar System Exploration

ikenbot:

Sun’s Shock Waves May Have Staggered Solar System’s Planet Formation

Our solar system’s planets may have formed at differing times, determined by shock waves flowing from the young sun, one astronomer suggests.

Image: Solar shockwaves would have produced proto-planetary rings at different times, meaning the planets did not form simultaneously. Credit: ESO

This theory posits that Earth is one of the youngest planets in the solar system, along with Mercury, Venus and Mars.

In a new paper, Tagir Abdylmyanov, an associate professor from Kazan State Power Engineering University in Russia, describes his idea and suggests it presents a possible new way of predicting where planets will form in young star systems.

“Studying the brightness of stars that are in the process of forming could give indications as to the intensity of stellar shock waves,” he said in a statement. “In this way we may be able to predict the location of planets around far-flung stars millions of years before they have formed.”

The theory has not been published in a peer-reviewed journal. Abdylmyanov presented his ideas this week at the European Planetary Science Congress in Madrid, Spain.

Eyeing the early solar system

Abdylmyanov adapted his own mathematical models by adding a solar system formation theory proposed by Japanese astrophysicists in 1985 in the book “Protostars and Planets II,” a University of Arizona publication that detailed planetary theory at the time.

In the decades-old paper, the Japanese scientists suggested that the solar system began with a solar nebula that gradually evolved to form clumps of dust that gelled to make protoplanets and then planets. Abdylmyanov takes that research a step further and says the planets formed at different times instead of at the same time.

Full Article

ikenbot:

Sizing Up a New Measuring Ruler for The Solar System

The sun still shines as bright, but according to the International Astronomical Union (IAU), its precise distance from us has just changed.

At a recent meeting of the IAU in Beijing, China, members unanimously voted to redefine the astronomical unit, or AU, which has long served as the fundamental unit of distance between objects in the solar system. According to the voters, the official definition of the AU is now exactly 149,597,870,700 metres, and the unit should be written “au”.

Historically, calculating the astronomical unit was based on the average distance between Earth and the sun, or 149,597,870,691 metres. An amendment in 1976 complicated things by also tying the unit to the sun’s mass.

Although the recent decision doesn’t alter the value by much, it simplifies things and should improve the accuracy of distance measurements over time.

“The old definition was good when we were not able to measure distance precisely in the solar system,” says Sergei Klioner of the Technical University of Dresden, Germany, who has been calling for the change since 2005.

With current technology, astronomers can measure distances directly with lasers and space probes, making it possible to give exact values in astronomical units.

(via kenobi-wan-obi)

expose-the-light:

Solar System Lollipops by Vintage Confections

(via physicsmajor)

ikenbot:

Cassini: Atlas in the Distance

The Cassini spacecraft looks past Saturn’s main rings to spy the tiny moon Atlas, which orbits between the main rings and the thin F ring.

The main rings are closer to the spacecraft than Atlas is, and the moon appears as only a small, white dot in the center of the image. This view looks toward the northern, sunlit side of the rings from just above the ringplane.

strictlyastronomy:

As a follow-up to my previous post about watching golfballs hit the moon at 100,000 miles an hour, here’s a guide to the Perseids and how to enjoy them.

  • What are the Perseids?  They are particles shed by Comet 109P/Swift-Tuttle, a periodic comet that last passed near Earth in 1992.  Composed of mostly silicate minerals, the typical meteor particle, or meteoroid, is about the size of a grain of sand.  The motion of the Earth through its orbit carries us toward “streams” of these particles left behind in the comet’s wake; our relative motion toward them makes the particles encounter the Earth at a relative velocity of tens to hundreds of thousands of miles per hour.  They meet the upper atmosphere and vaporize as they reach temperatures of thousands of degrees for a few brief seconds; we see their remnants as bright streaks of light commonly known as “shooting stars”.  The Perseid shower is one of the year’s more notable events, leading sometimes to hundreds of meteors per hour being seen.
(Comet Swift-Tuttle in 1992.  Credit & copyright: Chris Cook, 2002)
  • How often do they happen? The Perseids are an annual event each August, and has been happening at least since antiquity.  Last seen exactly 150 years ago during the Civil War, Swift-Tuttle was somewhat considered “lost” because its observations in 1862 were not sufficiently precise to nail down its orbit.  The comet “announced” its coming return to the inner solar system during the 1991 Perseid shower with a huge burst of activity during the early morning hours over East Asia.  Speculation as to whether this feature represented material recently shed by the comet was well founded; the comet re-appeared in Earth’s skies about a year later. Each time the comet returns, a new stream of particles is shed and the shower is replenished.
  • Why are meteors important?  There’s a lot of science involved.  So many comets have come and gone over the history of the solar system that the inner part is chock full of dust particles.  These particles constantly rain down on the Earth and other terrestrial planets, bringing many tons of cosmic material per year; early in the solar system’s history, this may have included the essential components needed in the chemistry of life.  The particles are thought to be relatively pristine, in the sense that they avoided the thermal shocks and chemical mixing that occurred in the solar nebula.  So a meteor seen streaking across our skies is a glowing messenger from the earliest times of our planetary system, telling us what conditions were like then.
  • Do I need a telescope to observe the Perseids?  Nope!  Meteor showers are a phenomenon requiring no special equipment at all; in fact, binoculars and telescopes allow views of such relatively small parts of the sky that they’re mostly ineffective for meteor observing.  Rather, showers like the Perseids contain many larger particles, which make for brighter meteors, and the best instruments to observe them are unaided human eyeballs.  Our eyes are pretty sensitive once dark adaptation has occurred, and we can see a very large area of sky at a time with them, increasing the chances of seeing meteors.
  • When should I look for Perseid meteors?  The shower peaks in intensity around August 11-13, so it’s going on right now — even during daylight hours.  However, for nighttime observing, the hours between midnight and dawn are best, because of the relative speed difference between the meteors and the Earth.  Before midnight, we’re facing away from the direction the Earth moves in its orbit around the Sun, so to be seen the meteors have to “catch up” to us.  After midnight, we’re facing the direction of motion and the relative speeds are highest.  Speed correlates with meteor brightness (for a given particle size), so you’re likely after midnight to see fainter meteors as a result.
  • What part of the sky should I look toward?  The Perseids can be seen in any part of the sky, but they appear to “radiate” from a point in the constellation Perseus.  In August, that constellation is rising in the northeastern sky toward midnight in the Northern Hemisphere.  So facing northeast aligns the observer with the direction from which the meteors appear to originate and increases the chances they’ll be seen before burning out.  Also, choice of seating is important, and a reclining lawn or lounge chair is highly recommended.  Staring upwards for hours at a time is otherwise rough on the neck muscles!
(Image credit: accuweather.com)
  • What can I expect to see? In an average year, observers can typically expect about one meteor per minute during the shower’s peak.  The rate is somewhat variable, and at times several will be seen per minute.  The Perseid shower is known for lots of bright, slow-moving fireballs, some of which explode at the end of their travel in a “terminal burst”.  At times these fireballs are bright enough to cast shadows on the ground.  There is rarely obvious color in meteors, but the Perseids tend toward a pale yellow, possibly due to emission of light from ionized sodium atoms.  The Perseids, one of the most reliable meteor showers of the year, rarely fail to impress!
  • Will the Moon be a problem?  Yes and no.  This year’s shower peaks a few days after the Moon is at last quarter, meaning two things: (1) The early part of the night will be Moon-free, and (2) After the Moon rises, it will present some interference.  Moonlight adds to the sky background, making the faintest Perseids difficult to see.  But don’t worry — the brightest meteors will easily outshine this light.  The main tip here is to not look in the direction of the Moon, to keep its light from ruining one’s dark adaptation.  One of the best tricks is to keep the Moon behind some obstruction, like a building or a tree, while maintaining a clear view to the northeast.  Remaining in shadow will minimize the interference.
  • Are my observations useful?  Yes!  Meteor watching is a great citizen-science opportunity.  Meteor science still relies on boots-on-the-ground observations from people, many of whom are amateur astronomers and other interested skywatchers. Ways to participate can be found here, here and here.  Having multiple people at one observing site helps in collecting observations, since several individuals can cover more of the sky at once than one person.  But one person can still see a lot of sky, and solo observations are quite useful.
  • Finally, stay warm, as the predawn hours in August can be cold in many parts of the Northern Hemisphere.  My meteor watching inevitably involves a thermos of hot coffee to help ward of the chill and drowsiness.  
Good luck!  And let us know what you see!

Additional resources:

(via project-argus)