Category Archives: General

ANSMET

Samples recovered from recent seasons include rare and scientifically valuable pieces of Mars and Moon, as well as rocks formed very early during the formation and evolution of the solar system that hold clues to the origin of volatiles, planets and the organic compounds essential to life.

Video

Cassini and Planet 9

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LOL. I’ve been getting quite a kick out of some of the hoopla surrounding “Planet 9” and saw the stories about how Cassini’s orbit was getting knocked about by the gravity of said planet.

I’ve even seen claims that NASA  is projecting a huge hologram into the sky in order to hide the sight of “Planet 9” coming right at us, after all according to these people,  it is supposed to be on a track to hit is in April and by my reckoning there is less than three-weeks left.

One tiny problem, we don’t even know for sure if “Planet 9” even exists, to say nothing about the rest of it. Although I would love to believe NASA could produce a big hologram like that, but no sadly they can’t.  Oh well, it makes for some good science fiction.

Anyway to address the Cassini’s orbital perturbations,  the Cassini team has this to say:

Saturn Spacecraft Not Affected by Hypothetical Planet 9

Contrary to recent reports, NASA’s Cassini spacecraft is not experiencing unexplained deviations in its orbit around Saturn, according to mission managers and orbit determination experts at NASA’s Jet Propulsion Laboratory in Pasadena, California.

Several recent news stories have reported that a mysterious anomaly in Cassini’s orbit could potentially be explained by the gravitational tug of a theorized massive new planet in our solar system, lurking far beyond the orbit of Neptune. While the proposed planet’s existence may eventually be confirmed by other means, mission navigators have observed no unexplained deviations in the spacecraft’s orbit since its arrival there in 2004.

“An undiscovered planet outside the orbit of Neptune, 10 times the mass of Earth, would affect the orbit of Saturn, not Cassini,” said William Folkner, a planetary scientist at JPL. Folkner develops planetary orbit information used for NASA’s high-precision spacecraft navigation. “This could produce a signature in the measurements of Cassini while in orbit about Saturn if the planet was close enough to the sun. But we do not see any unexplained signature above the level of the measurement noise in Cassini data taken from 2004 to 2016.”

A recent paper predicts that, if data tracking Cassini’s position were available out to the year 2020, they might be used to reveal a “most probable” location for the new planet in its long orbit around the sun. However, Cassini’s mission is planned to end in late 2017, when the spacecraft — too low on fuel to continue on a longer mission — will plunge into Saturn’s atmosphere.

“Although we’d love it if Cassini could help detect a new planet in the solar system, we do not see any perturbations in our orbit that we cannot explain with our current models,” said Earl Maize, Cassini project manager at JPL.

Image and press release: The Cassini-Huygens mission is a cooperative project of NASA, ESA and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate in Washington.

Raindrops

NASA and Japan Aerospace Exploration Agency Global Precipitation Measurement (GPM) mission are focusing on raindrops.

I will say if they looked at where I was yesterday they had plenty to look at with nearly four centimeters of rain in an hour streams were out of their banks.

Here’s the scoop from NASA:
“The drop size distribution is one of many factors that determines how big a storm will grow, how long it will last and how much rain it will ultimately produce,” said Joe Munchak, research meteorologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We’ve never been able to see how water droplet sizes vary globally until now.”

Storm clouds contain a wide variety of drop sizes that ultimately fall as rain or snow. In general, in the cores of clouds the drops tend to be bigger because they collide with each other and aggregate as they fall towards the Earth’s surface, while smaller droplets occur at the edges and higher altitudes. Drops tend to be small when they miss colliding into others or break apart. Scientists refer to the number of drops and snowflakes of different sizes at various locations within a cloud as the “particle size distribution.”

In order to accurately know how much precipitation is falling in a storm, scientists need to understand the ratio of large drops to smaller or medium sized drops. Previously, researchers had to make assumptions of the ratio because earlier studies were conducted in isolated locations and global data were limited, said Munchak.

“Without knowing the relationship or the ratio of those large drops to the smaller or medium sized drops, we can have a big error in how much rain we know fell and that can have some big implications for knowing long term accumulations which can help with flash flood predictions,” said Munchak.

“Without knowing the relationship or the ratio of those large drops to the smaller or medium sized drops, we can have a big error in how much rain we know fell and that can have some big implications for knowing long term accumulations which can help with flash flood predictions,” said Munchak.

With GPM’s three-dimensional snapshots of drop size distribution, scientists can also gain insight into the structure of a storm and how it will behave. Drop size distribution influences storm growth by changing the rate of evaporation of rain as it falls through dry air, said Munchak. Smaller drops, for instance, will tend to evaporate faster and subsequently cool the air more. This leads to stronger flow of downward moving air that can cause damaging winds when they reach the ground. However, these same downdrafts can interfere with the upward flowing air that fuels the storm and cause the storm to weaken or dissipate.

“GPM measurements will really help predict these complex interactions that depend in part of the drop size distribution,” said Munchak.

GPM was launched in 2014 and carries the first Dual-frequency Precipitation Radar (DPR) to fly in space, as well as a multi-channel GPM Microwave Imager (GMI). The DPR makes detailed 3D measurements of rainfall, while the GMI uses a set of 13 optimized frequencies to retrieve heavy, moderate, and light precipitation measurements at the Earth’s surface. As GPM improves our understanding of precipitation from space, that information will be vital in improving weather models and forecasts.

For more information on GPM, visit: http://www.nasa.gov/GPM

Hat tip to SpaceRef

Happy Equinox!

For me it is the spring equinox and I will be happy to have the warmer temperatures we will (or should have) for the next few months. Those in the southern hemisphere this is the autumn equinox and shorter days are ahead.

The time of the equinox is 04:30 UTC.

The video is from the Kurdistan Planetarium

Uranus

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The planet Uranus appears to be pretty much a featureless ball. Probably because the planet unlike the other gas giants lacks any substantial internal heat and the clouds don’t really billow above the upper haze layers.

We also view the planet from above the poles because the axial tilt of the planet is nearly 98 degrees! Check out our Uranus data for more on this most interesting planet and its moons which by the way has not been visited since the Voyager missions.

This image is from the Voyager 2 mission, credit: NASA/JPL

Saturn

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Saturn from TNP:

In Roman mythology, Saturn is the god of agriculture. The associated Greek god, Cronus, was the son of Uranus and Gaia and the father of Zeus (Jupiter). Saturn is the root of the English word “Saturday” (see Appendix 5).

Saturn has been known since prehistoric times. Galileo was the first to observe it with a telescope in 1610; he noted its odd appearance but was confused by it. Early observations of Saturn were complicated by the fact that the Earth passes through the plane of Saturn’s rings every few years as Saturn moves in its orbit. A low resolution image of Saturn therefore changes drastically. It was not until 1659 that Christiaan Huygens correctly inferred the geometry of the rings. Saturn’s rings remained unique in the known solar system until 1977 when very faint rings were discovered around Uranus (and shortly thereafter around Jupiter and Neptune).