Mars’ Orcus Patera – a fascinating enigma
Orcus Patera, an elliptical depression near Mars’ equator, is a mystery … but it sure makes a pretty picture.
Orcus Patera is a 380 kilometer by 140 kilometer, elliptical depression located between the Elysium Mons and Olympus Mons. A rim, some 1800 meters high, encircles the depression, while its floor descends 400 to 600 meters below the nearby plains.
“Patera” is usually used for volcanic craters with deep, complex, or irregular shapes. Orcus Patera does lie in a known, ancient volcanic region, but its actual origin remains in doubt.
Orcus Patera could have begun as a circular impact crater that was later deformed by by tectonic forces. Tectonic activity in the region is evidenced by the presence of graben and wrinkle-ridges in and around the feature.
Another suggested origin for Orcus Patera involves two or more, overlapping craters where the inner rims have been eroded away. There is evidence of erosion within the depression, as well as multiple episodes of material deposition, that could have helped hide a multiple-crater origin.
Those of us who have skimmed stones across a pond may think of another explanation. Orcus Patera could be the scar left by an object impacting at a very shallow angle.
Whatever its origin, Orcus Patera remains another fascinating feature of the Red Planet.
References:
- Mars’s mysterious elongated crater. 27 August 2010. ESA Space Science.
- Mars. World Book at NASA.
- Graben. Wikipedia.
- Wrinkle-ridge. Wikipedia.
Asteroid Discoveries, 1980 – 2010
More thah half a million asteroids have been discovered since 1980. Szyzyg just posted on Youtube this fascinating video illustrating the history of asteroid discovery.
Musopen needs your help to set music free
Musopen, the non-profit library of copyright free music needs your help to purchase and release music into the public domain.
From the project website:
“Right now, if you were to buy a CD of Beethoven’s 9th symphony, you would not be legally allowed to do anything but listen to it. You wouldn’t be able to share it, upload it, or use it as a soundtrack to your indie film- yet Beethoven has been dead for 183 years and his music is no longer copyrighted. There is a lifetime of music out there, legally in the public domain, but it has yet to be recorded and released to the public.”
Musopen is trying to raise at least $11,000 before 14 September 2010. Go to the Kickstarter project website and pledge your donation now.
Kickstarter is an interesting way to fund creative and ambitious ideas.
The Moon is Shrinking
Yes, the Moon (our Moon, Luna) is shrinking … but scientists are not surprised.
NASA’s Lunar Reconnaissance Orbiter has found lobate scarps over much of the lunar surface. A lobate scarp is a stair-step-like feature. It results from a reverse thrust fault where one side is pushed up and over the other side. The scarp appears as a slanting wall that can be hundreds of meters high and hundreds of kilometers long. Lobate scarps were first seen on the Moon through Apollo 15, 16, and 17 cameras.
Reverse thrust faults result when the cooling and shrinking interior causes the crust material to compress and crinkle. Since so many faults are found all over the Moon, an explanation must be global.
It is currently believed that the Moon formed 4.527 ± 0.010 billion years ago when a small protoplanet impacted the early Earth, spraying debris into surrounding space. This material coalesced under the influence of gravity, forming a molten body that has been cooling and solidifying ever since.
Some lobate scarps found on the Moon are relatively fresh, perhaps as young as 800 million years old. In comparison, most lunar features (many craters and the maria) are over 3.5 billion years old.
“Before LRO launched, it was common to think of the Moon as dead, but after a year of observations we are finding that the Moon is a dynamic world,” says Mike Wargo, chief lunar scientist at NASA.
References:
- NASA’s LRO Reveals ‘Incredible Shrinking Moon’. NASA Lunar Reconnaissance Orbiter Mission. 19 August 2010.
- The Moon is shrinking. Astronomy Now Online. 19 August 2010.
- Geological Nomenclature and Terminology. WikiSpaces.
- Moon. Wikipedia.
- Full Moon by Luc Viatour. WikiMedia Commons. 07 October 2006.
Jack Horkheimer passes away at age 72
“Greetings, greetings, fellow stargazers!”
So, Jack Horkheimer would begin episodes of “Star Hustler” (later, renamed to “Star Gazer”), the nationally-syndicated, weekly, naked-eye astronomy show produced in cooperation with the Miami Museum of Science and the Space Transit Planetarium.
Jack Foley A. Horkheimer, executive director of the Miami Planetarium since 1973, is best known for his television show in which he entreated people to step out and look up at the night sky. Each week, Mr. Horkheimer would give a lively and, perhaps, corny presentation about some featured astronomical object or event. Mr. Horkheimer signed off from each show by telling his viewers to “keep looking up!”
Episodes of the show and other videos can be downloaded for free from the show’s website.
In familiar Horkheimer style, he wrote this, his own epitaph:
Keep Looking Up was my life’s admonition,
I can do little else in my present position.
References:
- Jack Horkheimer: Ambassador to the Stars. Kelly Beatty. Sky & Telescope. 20 August 2010.
- Jack Horkheimer: Star Gazer. Show Homepage.
- Horkheimer’s Bio. at the Miami Space Transit Planetarium.
Jupiter’s Great Red Spot set for encounter
Jupiter’s Great Red Spot (GRS) is set for an encounter with another vortex, Oval BA (a.k.a., “Red Spot Jr.” or “Red Jr.”).
Jupiter rotates differentially, meaning that different latitudes rotate around the planet at different rates. Since GRS and Oval BA are at different latitudes, they pass each other about every two years.
Oval BA formed from the merger of three white ovals, two in 1998 and a third in 2000. Oval BA began to darken and redden in 2005, more so after its 2006 encounter with GRS.
Astronomers are waiting to see what will result from interactions of the two storms during this year’s encounter.
References:
- Jupiter’s red spots in double act. Skymania. 19 August 2010.
- When whirls collide on Jupiter. Skymania. 21 July 2006.
- Atmosphere of Jupiter. Wikipedia.
Gmail Voice and Video Chat for Linux
Google released a voice and video chat plugin today for Debian-based Linux distributions.
Have any of you had a chance to try it yet?
Links:
- Google Video and Voice Chat Download
- Use Linux? Now you can video chat too. Tristan Schmelcher. Gmail Blog. 19 August 2010.
- Gmail Voice and Video Chat – Too Little too Late?. Susan Linton. Linux Journal. 20 August 2010.
Intel buys McAfee
In an all-cash, US$7.68 billion deal, Intel Corp. buys security software giant, McAfee, Inc.
“Everywhere we sell a microprocessor, there’s an opportunity for a security software sale to go with it,” said Paul Otellini, Intel’s CEO.
Read more about it at http://techcrunch.com/2010/08/19/intel-buys-cyber-security-giant-mcafee-for-7-68-billion-in-cash/.
Mt. Vesuvius: New thoughts about an ancient disaster
Mount Vesuvius erupted in 79 CE, burying the Pompeii, Herculaneum, and the surrounding region. It is generally accepted that those not killed by falling rocks and collapsing buildings, were killed by suffocation by ash and volcanic gases.
A new study from the Naples Observatory implies that Mt. Vesuvius’ victims may have died from an extreme heat surge, not from suffocation.
Victims in Pompeii, 10 kilometers from Mt. Vesuvius, may have been exposed to temperatures up to 150 degrees Celsius. Only a few seconds of exposure to this temperature would have been lethal, even for those inside buildings. Temperatures over 260 degrees Celsius would have been experienced closer to the volcano.
Models indicate that a deadly heat wave could have traveled up to 20 kilometers from the volcano. This makes the current evacuation radius of 8 kilometers seem insufficient. The modern city of Naples, with a population of about 1 million, is only about 9 kilometers from Mt. Vesuvius. More than 3 million people are at risk should Mt. Vesuvius have another eruption like the one that destroyed Pompeii.
Read more at http://news.discovery.com/earth/are-we-underestimating-mt-vesuvius.html.
Suits Allege User Web Tracking by Big Corp.
A suit filed on 10 August 2010 in the U.S. District Court for the Central District of California alleges that a group of Web sites, including those owned by Warner Bros. Records, Disney, and others.
The suit, filed on behalf of a group of minors and their parents, is centered around Clearspring Technologies, which produces software that is being used to deliver advertisements. Apparently, Clearspring Technologies set Flash cookies on users’ computers without their knowledge. Moreover, “Web sites working with Clearspring knew users weren’t just tracked at sites owned by affiliates, but were followed without their knowledge wherever they went online [1]), the suit alleges.
A similar lawsuit was filed in July, naming Quantcast, ABC, NBC, and six other companies [2].
Both cases seem to revolve around use of ‘Flash cookies.’ A 2009 study [3] on “Flash Cookies and Privacy” states:
This is a pilot study of the use of ‘Flash cookies’ by popular websites. We find that more than 50% of the sites in our sample are using flash cookies to store information about the user. Some are using it to ‘respawn’ or re-instantiate HTTP cookies deleted by the user. Flash cookies often share the same values as HTTP cookies, and are even used on government websites to assign unique values to users. Privacy policies rarely disclose the presence of Flash cookies, and user controls for effectuating privacy preferences are lacking.
The plaintiffs state that the kind of information gathered by Clearspring Technologies and its affiliates “was personal and far-reaching.” Revealed information may include name, gender, age, race, number of children, education level, location, email addresses, telephone numbers, sexual preference, financial status, reading preferences, and so on.
References:
- Suit alleges Disney, other top sites spied on users. 14 August 2010. Greg Sandoval. cnet news.
- Lawsuit Tackles Files That ‘Re-Spawn’ Tracking Cookies. 30 July 2010. Jennifer Valentino-DeVries. Digits. The Wall Street Journal Blogs.
- Flash Cookies and Privacy. 10 August 2009. Soltani et al. Social Science Research Network.