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Venice News Updates

News of Venice, CA and Marina del Rey CA

NASA Asks: Will We Know Life When We See It?

Posted by :reta On : June 27, 2018
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Category: Bob Eklund Column, Uncategorized

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(Photo courtesy of NASA.)

(Photo courtesy of NASA.)

Note: Bob Eklund gets his info from press releases.

Bob Eklund and Looking Up Column

Bob Eklund and Looking Up Column

 

 

In the last decade, we have discovered thousands of planets outside our solar system and have learned that rocky, temperate worlds are numerous in our galaxy. The next step will involve asking even bigger questions. Could some of these planets host life? And if so, will we be able to recognize life elsewhere if we see it?

A group of leading researchers in astronomy, biology and geology has come together under NASA’s Nexus for Exoplanet System Science, or NExSS, to take stock of our knowledge in the search for life on distant planets and to lay the groundwork for moving the related sciences forward.

“We’re moving from theorizing about life elsewhere in our galaxy to a robust science that will eventually give us the answer we seek to that profound question: Are we alone?” said Martin Still, an exoplanet scientist at NASA Headquarters, Washington.

In a set of five review papers published last week in the scientific journal Astrobiology, NExSS scientists took an inventory of the most promising signs of life, called biosignatures. The paper authors include four scientists from NASA’s Jet Propulsion Laboratory in Pasadena, California. They considered how to interpret the presence of biosignatures, should we detect them on distant worlds.

The assessment comes as a new generation of space and ground-based telescopes are in development. NASA’s James Webb Space Telescope will characterize the atmospheres of some of the first small, rocky planets. There are plans for other observatories—such as the Giant Magellan Telescope and the Extremely Large Telescope, both in Chile—to carry sophisticated instruments capable of detecting the first biosignatures on faraway worlds.

NASA’s First Deep-Space CubeSats Say: “Polo!”

Posted by :reta On : May 12, 2018
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Category: Bob Eklund Column

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Note:  Based on press release from NASA/JPL

Bob Eklund Looking Up Column

Bob Eklund
Looking Up Column

NASA has received radio signals indicating that the first-ever CubeSats headed to deep space are alive and well. Engineers will now be performing a series of checks before both CubeSats enter their cruise to deep space.

Mars Cube One, or MarCO, is a pair of briefcase-sized spacecraft that launched May 5 along with NASA’s InSight Mars lander from Vandenberg Air Force Base in Central California. InSight is a scientific mission that will probe the Red Planet’s deep interior for the first time. The name stands for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport.

The twin MarCO CubeSats are on their own separate mission: rather than collecting science, they will follow the InSight lander on its cruise to Mars, testing out miniature spacecraft technology along the way.

Both were programmed to unfold their solar panels soon after launch, followed by several opportunities to radio back their health.

“Both MarCO-A and B say ‘Polo!’ It’s a sign that the little sats are alive and well,” said Andy Klesh, chief engineer for the MarCO mission at NASA’s Jet Propulsion Laboratory in Pasadena, California, which built the twin spacecraft.

A couple of weeks will be spent assessing how the MarCO CubeSats are performing. If they survive the radiation of space and function as planned, they’ll fly over the Red Planet during InSight’s entry, descent and landing in November.

Solar System’s First Interstellar Visitor Dazzles Scientists

Posted by :reta On : November 24, 2017
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Artist’s impression of the interstellar asteroid `Oumuamua
European Southern Observatory/M.Kornmesser

Bob Eklund Looking Up

Bob Eklund
Looking Up

Astronomers recently scrambled to observe an intriguing asteroid that is passing through our solar system on a steep trajectory from interstellar space—the first confirmed object from another star.

Now, new data reveal the interstellar interloper to be a rocky, cigar-shaped object with a somewhat reddish hue. The asteroid, named ‘Oumuamua by its Hawaiian discoverers, is up to one-quarter mile long and highly-elongated—perhaps 10 times as long as it is wide. That aspect ratio is greater than that of any asteroid or comet observed in our solar system to date.

The observations and analyses suggest this unusual object had been wandering through the Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with our star system.

Immediately after its discovery, telescopes around the world, including ESO’s Very Large Telescope in Chile, were called into action to measure the object’s orbit, brightness and color. Urgency for viewing from ground-based telescopes was vital to get the best data.

Combining the images from the ESO telescope with those of other large telescopes, a team of astronomers led by Karen Meech of the Institute for Astronomy in Hawaii found that ‘Oumuamua varies in brightness by a factor of 10 as it spins on its axis every 7.3 hours. No known asteroid or comet from our solar system varies so widely in brightness, with such a large ratio between length and width. The most elongated objects we have seen to date are no more than three times longer than they are wide.

Watching a Volatile Stellar Relationship

Posted by :reta On : June 16, 2017
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Category: Bob Eklund Column, Looking Up Column

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raqr_w11
 (Photo courtesy of Chandra X-Ray Center.)

Note: This is a press release from Chandra X-Ray Center and NASA/Marshall Space Flight Center.

Bob Eklund Looking Up Column

Bob Eklund
Looking Up Column

 

In biology, “symbiosis” refers to two organisms that live close to and interact with one another. Astronomers have long studied a class of stars—called symbiotic stars—that co-exist in a similar way. Using data from NASA’s Chandra X-ray Observatory and other telescopes, astronomers are gaining a better understanding of how volatile this close stellar relationship can be.

R Aquarii (R Aqr, for short) is one of the best known of the symbiotic stars. Located at a distance of about 710 light-years from Earth, its changes in brightness were first noticed with the naked eye almost a thousand years ago. Since then, astronomers have studied this object and determined that R Aqr is not one star, but two: a small, dense white dwarf and a cool red, giant star.

The red giant star has its own interesting properties. In billions of years, our Sun will turn into a red giant once it exhausts the hydrogen nuclear fuel in its core and begins to expand and cool. Most red giants are placid and calm, but some pulsate with periods between 80 and 1,000 days like the star Mira and undergo large changes in brightness. This subset of red giants is called “Mira variables.”

The red giant in R Aqr is a Mira variable and undergoes steady changes in brightness by a factor of 250 as it pulsates, unlike its white dwarf companion that does not pulsate. There are other striking differences between the two stars. The white dwarf is about ten thousand times brighter than the red giant. The white dwarf has a surface temperature o.

Rare High-Resolution of Exploded Star

Posted by :reta On : April 29, 2017
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Courtesy of W.M. Keck Observatory

Courtesy of W.M. Keck Observatory

Note: This is a press release from W.M. Keck Observatory.

Bob Eklund Looking Up

Bob Eklund
Looking Up

Scientists will now be able to measure how fast the universe is truly expanding with the kind of precision not possible before.

This, after an international team of astronomers led by Stockholm University, Sweden, captured four distinct images of a gravitationally lensed Type Ia supernova, named iPTF16geu.

To get a high-resolution view, the discovery team used the W. M. Keck Observatory’s OSIRIS and NIRC2 instruments with laser-guided adaptive optics at near-infrared wavelengths.

This discovery is highly interesting to scientists because Type Ia supernovas can be used as a “standard candle” to calculate galactic distances.

A standard candle is an astrophysical object that emits a certain, known amount of light. In this case, the object is a Type Ia supernova, a class of dying stars that always explode with the same absolute brightness. If astronomers know such an object’s true luminosity, they can infer its distance from Earth. The dimmer the object, the farther away it is.

This rare discovery is made possible through gravitational lensing, a phenomenon that was first predicted by Albert Einstein in 1912. As light of the distant object passes by a massive object such as a galaxy cluster in the foreground, it gets bent by gravity, just as light gets bent passing through a lens. When the foreground object is massive enough, it will magnify the object behind it. In iPTF16geu’s case, its light was magnified by up to 50 times and bent into four separate images by a galaxy in front of it.

NASA Missions Harvest a Passel of ‘Pumpkin’ Stars

Posted by :reta On : November 3, 2016
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Bob Eklund Looking Up Column

Bob Eklund
Looking Up Column

Note: This is a press release from NASA Goddard Space Flight Center.

Astronomers using observations from NASA’s Kepler and Swift missions have discovered a batch of rapidly spinning stars that produce X-rays at more than 100 times the peak levels ever seen from the Sun. The stars, which spin so fast they’ve been squashed into pumpkin-like shapes, are thought to be the result of close binary systems where two Sun-like stars merge.

“These 18 stars rotate in just a few days on average, while the Sun takes nearly a month,” said Steve Howell, a senior research scientist at NASA’s Ames Research Center in Moffett Field, California, and leader of the team. “The rapid rotation amplifies the same kind of activity we see on the Sun, such as sunspots and solar flares, and essentially sends it into overdrive.”

The most extreme member of the group, a K-type orange giant dubbed KSw 71, is more than 10 times larger than the Sun, rotates in just 5.5 days, and produces X-ray emission 4,000 times greater than the Sun does at solar maximum.

Going Out in a Blaze of Glory: Cassini’s Grand Finale

Posted by :reta On : October 29, 2016
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Bob Eklund Looking Up Column

Bob Eklund
Looking Up Column

With the conclusion of the international Cassini mission orbiting Saturn and its moons set for Sept. 15, 2017, the spacecraft is poised to soon begin a thrilling two-part endgame.

Cassini will enter the first part of this denouement on Nov. 30, 2016, when the spacecraft begins a series of 20 passes just beyond the outer edge of the main rings. These weekly loops around Saturn are called the F ring orbits, and they send the spacecraft high above and below the planet’s poles.

Cassini’s final phase—called the Grand Finale—begins in earnest in April 2017. A close flyby of Saturn’s giant moon Titan will reshape the spacecraft’s orbit so that, instead of passing outside the rings, it passes through the gap between the rings and the planet. The spacecraft is expected to make 22 plunges through this gap—an unexplored space only about 1,500 miles wide—beginning with its first dive on April 27.

The mission will come to a dramatic end on Sept. 15, 2017, after more than 13 years studying Saturn, its rings and its moons. On that day, Cassini will dive into Saturn itself, returning data about the chemical composition of the planet’s upper atmosphere until its signal is lost, after which the spacecraft is expected to burn up like a meteor.

Proxima Centauri: More Sun-Like Than We Thought?

Posted by :reta On : October 14, 2016
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sun.

Note:  Press release from Harvard-Smithsonian Center for Astrophysics.

 

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Bob Eklund
Looking Up

In August, astronomers announced that the nearest star, Proxima Centauri, hosts an Earth-sized planet (called Proxima b) in its habitable zone. At first glance, Proxima Centauri seems nothing like our Sun. It’s a small, cool, red dwarf star that’s only one-tenth as massive and one-thousandth as luminous as the Sun. However, new research by Harvard-Smithsonian Center for Astrophysics shows that it is Sun-like in one surprising way: It has a regular cycle of starspots.

Starspots (like sunspots) are dark blotches on a star’s surface where the temperature is a little cooler than the surrounding area. They are driven by magnetic fields. A star is made of ionized gases called plasma. Magnetic fields can restrict the plasma’s flow and create spots. Changes to a star’s magnetic field can affect the number and distribution of starspots.

Our Sun experiences an 11-year sunspot activity cycle. At the solar minimum, the Sun is nearly spot-free. At solar maximum, typically more than 100 sunspots cover less than one percent of the Sun’s surface.

The new study finds that Proxima Centauri undergoes a similar cycle lasting seven years from peak to peak. However, its cycle is much more dramatic. At least a full one-fifth of the star’s surface is covered in spots at once.

Hubble Telescope Spots Possible Water Plumes Erupting on Jupiter’s Moon Europa

Posted by :reta On : October 2, 2016
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Bob Eklund
Looking Up

Astronomers using NASA’s Hubble Space Telescope have imaged what may be water vapor plumes erupting off the surface of Jupiter’s moon Europa. This finding bolsters other Hubble observations suggesting the icy moon erupts with high-altitude water vapor plumes.

The observation increases the possibility that missions to Europa may be able to sample Europa’s ocean without having to drill through miles of ice.

“Europa’s ocean is considered to be one of the most promising places that could potentially harbor life in the solar system,” said Geoff Yoder, acting associate administrator for NASA’s Science Mission Directorate in Washington, D.C. “These plumes, if they do indeed exist, may provide another way to sample Europa’s subsurface.”

water

The plumes are estimated to rise about 125 miles before, presumably, raining material back down onto Europa’s surface. Europa has a huge global ocean containing twice as much water as Earth’s oceans, but it is protected by a layer of extremely cold and hard ice of unknown thickness.

The team, led by William Sparks of the Space Telescope Science Institute (STScI) in Baltimore, Maryland, observed these finger-like projections while viewing Europa’s edge as it passed in front of Jupiter.