Saturday, July 24, 2010

Big Star

Fascinating press release from European Southern Observatory:

"Using a combination of instruments on ESO’s Very Large Telescope, astronomers have discovered the most massive stars to date, one weighing at birth more than 300 times the mass of the Sun, or twice as much as the currently accepted limit of 150 solar masses."

Star 136a1 is the most massive star found yet. Since the time of Pierre Laplace, astronomers have believed that stars condensed from rotaing clouds of gas. How such clouds could become dense enough to start nuclear fusion has been a nagging puzzle. This immense star challenges the old theories.

If stars formed around tiny Black Holes, the inward pull of the singularity would cause the star to condense until fusion began. Presence of the singularity would allow stars to form with enormous sizes, hundreds of times our Sun's mass. The centre of star 136a1 would be a good place to find a Black Hole.

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Thursday, July 22, 2010

The Latest On Spirit

This is the view from Gusev Crater, Mars at local sunrise 5:51 PM on July 22, 2010 Universal Time. Earth once again leads the parade of planets prior to sunrise. Below, Jupiter and Venus form a tighter grouping. A Martian Galileo with a telescope could probably see Jupiter's moons at night. Earth's Moon, previously the limit of human exploration, may be visible on some nights.

No communication has been heard from the Spirit rover since March 22. Most likely Spirit has experienced a low-power fault, has turned off all subsystems, and gone to sleep. During this hibernation, the rover will use all available solar power to recharge her batteries. When there is sufficient battery charge, Spirit would be heard from again.

No word yet from ARES, the human expedition to Mars. It was due to land July 13. Perhaps the crew is alive but, like Spirit, unable to communicate.


Wednesday, July 21, 2010

One Small Step

The first video from the Moon's surface July 20, 1969. Prior to Apollo all of human history took place on the tiny dot of Earth. Since 1969 human exploration has spanned the short distance from Earth to Moon. We hope to see footage like this soon.


Thursday, July 15, 2010

Loss of Signal

This is the view you would see looking East from Gusev Crater at local sunrise, 1:14 PM Universal Time. Because of the speed of light, this image will not appear until 1:26 PM UT. Earth is slightly lower in the sky than last week and Venus higher, so they form a cluster with Jupiter between them. Observers on Earth will see Mars between Venus and Saturn, with a crescent Moon nearby. If Earth's Moon were bright enough to be seen from Mars, its orbit would span an angular distance 1/6 the Moon's diameter seen from Earth. All of human history, even the Apollo landings on the Moon, has taken place in a tiny patch of sky.

Mission Control in Houston often deals with loss of signal from spacecraft. More than one day after landing there is no word from Gusev Crater. The Spirit Rover, permanently lodged in Martian regolith, has not been heard from since March 13. The ARES spacecraft launched October 28, 2009 has not been heard from since beginning reentry. Many things could have gone wrong. The inflatable heat shield has never been tested in Martian conditions. The 3 main parachutes, which deploy at a speed over Mach 1, are another possible point of failure. There are many risks in landing a spacecraft on Mars.

Possibly the crew landed safely but the communications dish has not deployed. Signals between Earth and Gusev Crater are limited to the roughly 12 hours that Earth is visible in the sky. The crew's first priority is maintaining her own survival and that of the spacecraft. Possibly she is safely settling on Mars, but unable to communicate. If this ARES mission is not successful, hopefully others willl follow. There is still a possiblity of hearing a human voice from Mars.


Tuesday, July 13, 2010

A Landing on Mars

Our last view of Space. 62 km over Mars, this is the view from the ARES spacecraft at 5:55 PM Universal Time, 10 minutes from a landing scheduled for 6:05 PM UT. Because of the speed of light, this image will not reach Earth until 6:07 PM UT, by which time ARES will have landed. The dark area near the horizon is Gusev Crater, our target and site of the Spirit Rover.

Rendezvous and landing is a complex three-body dance involving Sun, Mars and spacecraft. Since leaving Earth orbit, ARES has been in an elliptical Hohmann transfer orbit to intercept Mars. Because ARES has been near the aphelion in her course, Mars has been overtaking the spacecraft from astern at 2.65 km/sec. In addition, Mars' gravity has been slowly pulling the spacecraft in, adding to the relative velocity. There is no turning back fron landing, neither has there been since Earth escape. Like unmanned probes of the past, ARES will use Mars' atmosphere to cancel her velocity.

Reentry is a fascinating problem in itself. 12 minutes from touchdown, ARES deploys a 20 meter diameter inflatable heat shield. A communications blackout begins as plasma builds around the spacecraft and the crew experiences deceleration up to 9 gees. In a matter of seconds the spacecraft slows from Mach 5 to less than Mach 1. 12 km from the surface the 3 main parachutes deploy, followed by heat shield separation. Less than 1 km from the surface, landing jets will fire. If all goes well, the spacecraft will touch down softly on the plains of Gusev Crater.

We would hear from the landed crew at 6:17 Universal Time.


Monday, July 12, 2010


Thoughts of masquerade parties and fixed constants are behind us. If all goes well. our ARES spacecraft launched October 28, 2009 is nearing Mars. A landing is scheduled in Gusev Crater at noon local time July 13, 2010. That is 1805 Houston time or 0805 in Hawaii. As the spacecraft is near aphelion of a Hohmann elliptical orbit, Mars will overtake the spacecraft from astern at 2.65 km/sec. 24 hours from landing, at a distance of 228000 km, the planet spans 1 degree and 42 minutes, about 3 times the size of the Moon seen from Earth. Deimos and Phobos are spectacularly arrayed alongside the planet. The next day will be very busy and exciting for the crew, but the view is worth every moment.


Sunday, July 11, 2010


A little fun: June 25-27 the place to be in Houston was the Apollo-Con science fiction convention. Being close to JSC, the most interesting speakers showed up. Last year the convention saw astronaut Stanley Love; this year scientist Paul Abell talked about NASA and asteroids. Apollo-Con has always welcomed people with Spacesuits.

This unusual outfit was seen in the Saturday night masquerade and hallways. It received reviews at Failure Weblog.

"That one chick in the polished silver tight-fitting robot suit that completely covered everything head to toe -- based on sorayama's "sexy robot" work -- was pretty swank though. (and evidently won the costume contest)"

Also Aazari's LiveJournal:

"A gorgeously done costume inspired by Sorayama's "Sexy Robot" images won best of show"

Hajime Sorayama is best known for his pinup paintings and "Sexy Robot" women. The attendees of Apollo-Con must have a high art IQ to recognise his images. The outfit also won a Best Workmanship award. Hopefully Sorayama will be pleased.

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Saturday, July 10, 2010

A Constant not Constant?

Back on Earth, there was an interesting story in Livescience:

Proton is Smaller Than Thought, new Measurement Finds

According to research published in the July 8 issue of NATURE, the size of the proton is 4 percent smaller than previously thought. The size of protons is thought to depend on the "Rydberg constant," a combination of values including Planck's value h and the speed of light c. This finding may indicate that the book value of the Rydberg is wrong, or something may be missing from Quantum Electrodynamics. "Either a theory must be revised or a supposed constant is wrong."

Being composed of values like h and c, a change in the Rydberg might mean that one or both of these changed. 330 years ago, in the time of Ole Roemer, many thought the speed of light infinite. Planck's value has only been measured for about a century. Recording these numbers in the pages of a book does not make them constant. The Rydberg is now a "supposed constant," preparing for a day when we may regard it as variable.

While we hear of Newton's gravitational constant and even a Hubble constant, a "speed of light constant" has never entered the vocabulary. Constant c is just a hypothesis barely 100 years old. It has spread through a school system that emphasis memorization by rote, telling students what to think but not how to think. Those who preach a constant speed of light look increasingly old and foolish. From a vantage point encompassing just a small part of the Universe, human concerns look small indeed.

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Wednesday, July 07, 2010

Parade of Planets

Last week we saw sunrise from the surface of Mars. Martian days (Sols) are 24 hours, 39 minutes long. 7 Sols later it is 8:36 AM July 8 UT on Earth, sunrise at Gusev Crater. Because of the 12-minute time delay, the image will appear 10:48 PM July 7 Hawaii time. Earth is just past her maximum angular separation from the Sun, and will soon be circling behind. Below Earth is Jupiter, fortuitously in position to be seen behind the inner planets. The new morning star below Jupiter is Venus. Mercury is on the other side of the Sun, visible every day at sunset. From the vantage point of Mars one can easily observe the inner worlds orbit the Sun.

This is Mars from 1.4 million km, the view from a human spacecraft 6 Sols from landing. Even 6 days out, Mars is 4 times the distance from Earth to the Moon. ARES was launched from Kennedy Space Center October 28, last day of the 2009 Mars launch window. This ARES, accelerating to Earth escape velocity, has been on a Hohmann transfer orbit to rendezvous with Mars on July 13, 2010. As the spacecraft is near aphelion in her elliptical path, Mars appears astern approaching at 2.65 km/sec. Apollo astronauts also saw the Moon overtake them from behind.

Even one day from landing Mars will be 235,000 km away, 2/3 the Earth-Moon distance. On that exciting day the crew will see the planet grow from a tiny disk to dominate the sky. ARES would have used all her cryogenic fuel escaping Earth, and must aerobrake to enter Mars' atmosphere. She will encounter Mars' atmosphere on the side facing the Sun, gaining about 300 m/sec from the planet's rotation. NASA technicians have launched 7 spacecraft to land on Mars in this manner, with only one failure. This ARES mission would have a good chance of success.

Once on Mars, the adventure would be just beginning. A resupply mission can not land until the next launch opportunity 26 months in the future. Lacking sufficient water and oxygen, the crew would have to find water on Mars. The possible scientific gains would make this risk more than worthwhile. The crew on Mars would every morning enjoy a view like this parade of planets.

Habitation Intention kindly hosts an "awe-inspiring" Carnival of Space!


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