Repost: Apollo 13: Eyewitness to the Explosion

By Mike Klesius

Odyssey, You Have a Problem.”
If five men in Houston had realized what they were seeing through a telescope on the evening of April 13, 1970, they could have radioed those words to the crew of Apollo 13, who was still trying to grasp what had just happened: an oxygen tank on their spacecraft had exploded en route to the moon.George Wyckliffe Hoffler was at the time a young NASA flight surgeon assigned to study cardiovascular data gathered from the Apollo astronauts during their spaceflights. On the second night of the mission, Hoffler was taking a break from studying for his medical boards, and had joined four other NASA employees on the roof of building 16A at the Manned Spacecraft Center, now the Johnson Space Center. There they watched a television monitor hooked up to a 16-inch Schmidt-Cassegrain telescope with a television camera mounted in place of the eyepiece. The monitor showed two dots flying in formation on their way to the moon: the brighter of the two was the spent third stage of the Saturn V launch vehicle; the dimmer one was the Apollo 13 spacecraft, which had separated from the third stage two days earlier.

The Apollo 13 spacecraft, as seen through the telescope, immediately after the oxygen tank blew. Credit: NASA

Every ten seconds the TV camera integrated, or updated, the image. “Between one ten-second integration and the next one,” says Hoffler, now retired in Titusville, Florida, “we can’t say exactly what second that was, the less bright dot was not a dot anymore. It was an expanded sphere, reflecting light. A disc. And I remember the guy who was in charge of the thing, Andy Saulietis,…he said, ‘What in the world is that?’ Every ten seconds it continued to grow a bit, and then started to fade as the gas dissipated into the vacuum of space. We watched it for two or three minutes I guess. In retrospect, none of us had the presence of mind to call next door to Mission Control and say, ‘Hey guys, you’ve got a problem.’ ”

What they were seeing was oxygen from the ruptured tank venting into space. In the vacuum, there was no atmospheric pressure to contain the expanding vapor. “We calculated the diameter of that reflecting sphere of gas surrounding the spacecraft to be approximately 25 miles. And it just blew out in just a few seconds,” says Hoffler. “It was under pressure, and when the cannister blew, the gas molecules jetted out with enormous velocity.” In this extended recording, astronauts Jim Lovell, Jack Swigert and Fred Haise remain calm as they report various readings to mission control. Lovell finally looks out the window to say that he sees some sort of gas being vented into space.

Hoffler notes that the anniversary of Apollo 13, which launched on April 11, overlaps with the April 12 anniversary of Yuri Gagarin’s flight as the first human in space in 1961, as well as the first flight of the space shuttle, launched on April 12, 1981. When offered the suggestion that April was a good month for human spaceflight, he says: “It was a bad month too.”

Read more: http://www.airspacemag.com/daily-planet/apollo-13-eyewitness-to-the-explosion-135059193/#ixzz2ynhDECBW

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The Rings of Saturn

More RAW images from the Cassini Space probe.  The upper one was taken on June 24, 2012 and received on Earth June 26, 2012. The camera was pointing toward SATURN-RINGS at approximately 1,235,364 miles (1,988,126 kilometers) away, and the image was taken using the CL1 and CL2 filters..

The lower one was taken on July 04, 2012 and received on Earth July 06, 2012. The camera was pointing toward TITAN at approximately 1,968,320 miles (3,167,704 kilometers) away, and the image was taken using the CB2 and CL2 filters.

Image Credit: NASA/JPL/Space Science Institute

Venus Transit

In the early hours of yesterday the planet Venus crossed in front of the Sun, a spectacle that won’t be seen again until 2117. Many people watched the spectacle (unless you were at NASA then blame the Australian worker who put his shovel through the cable carrying the footage)

What follows is a series of pictures of this amazing event.

 

Jupiter

If you look into the night sky over the next few months you may notice a very bright star, so bright that it outshines everything in the sky (Apart from the moon) that bright object is a planet. And what a planet it is.

Jupiter is the largest planet in the Solar system the large red spot in the above photo is a swirling violent storm that has existed for centuries, it is so large that our planet could fit into it 2 or three times. Small wonder that it is known as the “king of the planets”

Jupiter has been known to us since antiquity the ancient Chinese were aware of it. The Chinese astronomer Gan De wrote the first detailed accounts of the planet and it is alleged that he recorded the existence of another object next to it (probably Ganymede.) Because the moons are quite bright and a small telescope will reveal them, it is possible to view the moons with the naked eye. Simply block the glare of the planet behind a building or a tree as the story goes.

Of course the most famous person to study Jupiter was the son of a musician, a man by the name of Galileo Galilei. Galileo was born February 15th 1564. He was a pious Roman Catholic, educated in a monastery and seriously considering a career in the clergy instead studied Mathematics. A keen astronomer he refined the plans for the first telescope and one night in 1610 looked to the giant planet. Galileo saw “three fixed stars, totally invisible by their smallness” further observations showed that these stars moved independently to the other stars, one night one was missing. From this Galileo deduced that these weren’t stars, but other celestial bodies orbiting Jupiter. The four moons he discovered were Io, Europe, Callisto and Ganymede.

Through a modest telescope or even binoculars you should be able to make out the large disk of Jupiter and the 4 moons, if you’re immune to the cold you can watch them move slowly around the giant planet.

Draconids.

The Draconid meteor shower, which was last seen in 2005, is peaking right now with an unbelievable amount falling through the atmosphere. If you’re one of the lucky ones in the UK who isn’t stuck under a ton of cloud and rain get outside and have a look.

The October Draconids occour when he Earth crosses the debris stream from the comet 21P/Giacobini-Zinner. The particles from the comet (most the size of a grain of sand) enter the Earths atmosphere and burn up, creating these bright “shooting stars”

This years display was expected to be quite bad, the bright light coming from the moon is expected to wash out some of the fainter ones. However initial reports are good (295 per hour before the peak!) and again, in clear skies you should be in for a treat.

Also after the Draconids is the Orionids later in the month and the Leonids in November. Although not expected to be as active it’s always nice to see a meteor make its final plunge.

For all the latest as always start at http://meteorwatch.org/ (which may take some time to load since it’s struggling at the minute.

Updated 2212 08/10/2011

M45

NASA’s Astronomy photograph of the day (APOD) is a pretty sweet website, and some of the images are amazing. One such one is this image of M45, also known as the Pleiades or seven sisters.  As I wrote last years M45 is one of my top 10 things in the sky, it’s visible right now in the sky (look for the small group of stars that looks like a question mark) if you have a pair of binoculars get them out and watch the 6/7 stars become 1000’s

Rockets, Tatooine and a Super Earth

A busy few days is a good enough phrase to sum up the last few days. Not only did NASA announce its new heavy lift launcher, details of which can be found here but they also managed to lose track of a satellite.

Launched from Discovery back in 1991 the Upper Atmosphere Research Satellite (UARS) platform was designed to carry out observations of the Earths atmosphere, in particular the Ozone layer. Decommissioned in 2005 the Sattelite has been causing a nuisance to other objects including the International Space Station, which was forced to make an object avoidance maneuver in October last year.

UARS is expected to fall out of Orbit on September 24 according to NASA and upto 25 pieces may land, and here’s the best bit, over a 400-500km strip anywhere within 57°N and 57°S of the Equator. So most of the populated planet. Although worrying NASA have said the probabilityof being crushed under spacejunk is a cool 1 in 3,200.

Roscosmos announced that the next ferry flight to the ISS will take place on or around November 14.  The news came after investigators found the fault that caused the Progress supply craft to crash into Siberia. According to one Roscosmos spokesman; “Members of the emergency commission have determined the cause of the failure of the Soyuz carrier rocket’s third stage engine. It is a malfunction in the engine’s gas generator.”

Kepler keeps being the gift that keeps on Giving with the discovery of the “Tatooine” planet. This large saturn like planet is the first discovered to orbit a binary system. That is a system with two suns instead of one, hence Tatooine.

Best take a sweater

However unlike the fictional planet Luke would have a hard time wistfully staring at the binary sunset, Kepler 16b is cold enough to freeze the tongue off a Hutt lord. A gas giant the temperature is a nippy -70 to -100 F.

The two stars, about 200 light years from Earth in the constellation Cygnus, circle each other every 41 days. One star is small, red and dim, throwing off just 20 percent of the light of our sun. The other star, bigger and orange, generates about 70 percent of the light of our sun. Kepler 16B circles them both, taking 229 days to complete an orbit. As it does, it passes in front of each star, blocking a small fraction of their light.

Another 50 planets were added to the list on Monday including one “super Earth.”

The planet, dubbed HD85512b, circles an orange star somewhat smaller and cooler than our sun about 36 light-years away. The star, HD85512, is visible in the southern sky in the constellation Vela.

The newly found planet circles this star every 59 days, putting it at the edge of the “habitable zone” where water could exist if atmospheric conditions were right. No doubt this planet will be a target for the new Extremely Large Telescope when it comes online early next decade.

How to spot SN 2011fe

This week, while the moon is still not overly bright, you have a chance to see the death of a star: a supernova. Unfortunately, this stupendous event is taking place not in our own galaxy — where it would be readily visible to the naked eye — but in the galaxy M101.

The bursting star was first seen on Aug. 23 with the 48-inch Oschin Schmidt telescope at Palomar Mountain Observatory in California. First called PTF 11kly and now designated SN2011fe, the supernova was discovered shining at a magnitude of +17.2, but has been brightening rapidly ever since.

Within the next week, it might reach 11th magnitude — appearing to shine some 300 times brighter than when it was first seen (remember, the lower the figure of magnitude, the brighter the object). The threshold of naked-eye visibility is magnitude 6.5.

Astronomers have categorized this catastrophic stellar explosion as a Type Ia supernova. A type Ia supernova occurs when a tiny white dwarf star acquires additional mass by siphoning matter away from a companion star. When it reaches a critical mass, the heat and pressure in the center of the star spark a runaway nuclear fusion reaction, and the white dwarf explodes.

Such explosions are spectacularly bright. For example: Placed beside the sun at a distance where the sun would appear as a star barely visible to the naked eye, a Type Ia supernova would appear to shine five times brighter than the full moon!

The galaxy in which this supernova is located, M101, has a linear diameter of more than 170,000 light-years, making it among the biggest disk galaxies known. And it is located at a distance of about 24 million light-years, meaning that the explosion actually took place 24 million years ago. It’s taken that long for the light to get to us.

How to find it

In his Celestial Handbook, Robert Burnham, Jr. describes M101 as “one of the finest examples of a large face-on Sc type spiral and a beautiful object on long-exposure photographs.”

The Frenchman Pierre Mechain was the first to see this galaxy in 1781. Later that same year, it was observed by Charles Messier, who described it as appearing as “A nebula without star, very obscure and pretty large.”

Messier would later include this galaxy as the 101st object in the final (1781) version of his famous catalog of comet masqueraders, hence “M” (for Messier) 101. It was one of the first “spiral nebulas” identified as such, in 1851 by William Parsons, the third Earl of Rosse.

Today, M101 sometimes goes by the popular moniker “The Pinwheel Galaxy.” The name is quite appropriate, as observatory photographs show it as an impressive system with well-defined spiral arms.

It’s also at a very convenient location, forming an equilateral triangle with the two end stars of the Big Dipper’s handle, in the direction away from the Dipper’s bowl. It’s just 5 degrees east from the famous double star Mizar in the middle of the handle of the Big Dipper, and about the same distance east-northeast from Alkaid, the star that marks the end of the handle. Remember that your clenched fist held at arm’s length measures roughly 10 degrees.

As darkness falls this week, the Big Dipper can be seen about halfway up in the northwest sky, with its handle pointing upward. By around 3 a.m. local daylight time, the handle is very low above the northern horizon. So if you want to see M101, your best bet is to try looking during the early evening hours while it’s still reasonably high in the sky.

What to look for

M101’s magnitude is listed as +7.7, which is only about three times dimmer than the threshold of naked-eye visibility. But while it may seem that this galaxy would be relatively easy to see in a telescope or even binoculars, it should be stressed that it’s a rather challenging object to spot because of its great size and relatively low surface brightness. It is best seen under a very dark sky.

Inexperienced observers should be careful not to use too high a magnification with their telescopes. Faint and extended luminous objects are often evident only because of their contrast against the sky background.

In their book “Binocular Astronomy” (Willmann-Bell, Inc, 1992), authors Craig Crossen and Wil Tirion note that “as you look for M101, keep in mind that you are searching for an object with a diameter two-thirds the moon’s, but with a surface brightness not much greater than the night sky itself.”

Crossen and Tirion suggest using zoom binoculars at 12- to 15-power.  A small telescope (4 to 6 inches at 30x) might show a smudge of light; a larger instrument (8 to 10 inches at 45x) may reveal a few brighter patches of light, while even larger scopes (12 to 16 inches at 60x) might start bringing out the galaxy’s distinctive spiral structure. [Telescopes for Beginners]

And as for SN2011fe, it’s located in the southwest (lower left) quadrant of M101. If you can find the galaxy’s hazy patch, you just might also be able to discern the supernova as a tiny starlike speck of light within that area.

Are we overdue?

As a final note, three other supernovas have previously been seen in M101, in 1909, 1951 and 1970.

In contrast, in our own Milky Way galaxy, supernovas have been comparatively infrequent, the last three having been observed in 1054 (the remnants of which are the famous Crab Nebula), 1572 (extensively observed by Tycho Brahe and known as “Tycho’s Star”) and 1604 (extensively observed by Johannes Kepler and known as “Kepler’s Star”).

These three supernovas were dazzling objects, appearing for a time to rival Jupiter and even Venus.  The fact that it has been more than 400 years since the last such flare-up in our own galaxy seems to suggest we are long overdue for another.

Original article from Space.com 

Boom goes the star.

Astronomers are gearing up for what could be a “wild ride” after a “once in a generation” supernova was discovered only “hours” after it flared up.

The Supernova, called SN 2011fe, was detected by a group of astronomers at Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley and was found in M101 (Pinwheel galaxy.) “We caught this supernova very soon after explosion. PTF 11kly is getting brighter by the minute. It’s already 20 times brighter than it was yesterday,¹” said Peter Nugent, the senior scientist at Berkeley Lab who first spotted the supernova.

PTF 11kly (highlighted by the arrow) Brightens up on these three images taken over consecutive nights by the Palomar 48-inch telescope

It is believed that this type of supernova was the result of a white dwarf star siphoning off material from it’s companion star (like the system that gave us PSR J1719-1438) however unlike that system the white dwarf siphoned off enough material to begin fusing hydrogen into helium, crossing the  which results in one of the most violent explosions in the universe, eventually brightening until it outshines the host galaxy.

Because of the distance from the galaxy to ourselves of around 25 million light years away, and it should be visible under dark skies and with binoculars in the northern hemisphere soon.  It’s close location and the fact we pretty much saw this happening from the very beginning (well it happened 25 million years ago but you get the gist) means there is a wealth of data that can be gathered.

Supernovas are a handy way of measuring the distances of galaxies, since they occur under near identical circumstances they can be used as “standard Candles” to measure distances to a few hundred mega-parsecs. They also contributed to our understanding of the expansion rate of the universe and the existence of dark matter.

 

1http://newscenter.lbl.gov/feature-stories/2011/08/25/supernova/

 

 

 

 

Shine on you crazy object around PSR J1719-1438

“We’re about to begin a journey through the cosmos. We’ll encounter galaxies and suns and planets, life and consciousness coming into being, evolving, and perishing, worlds of ice and stars of diamond, atoms as massive as suns and universes smaller than atoms.” – Carl Sagan

Pulsars, lighthouses in the cosmos, blinking and hissing. In actuality a pulsar is the core of a dead star a neutron star, the hissing and blinking is a torrent of electromagnetic rays emitted from these small (around the size of a city) stars. One  PSR J1719-1438 is in the news at the minute. PSR J1719-1438 spins an incredible (but rather common) 5.7 ms, that’s 5.7 thousandths of a second! When astronomers were observing the pulsars they noticed the signals were “systematically modulated¹” every 130 minutes.  From that they managed to determine something was nearby influencing it with its gravity.

That something turned out to rather special, and a girls best friend. The object orbiting PSR J1719-1438 is a small companion white dwarf star. Around 70%  of these millisecond pulsars have them and they siphon off material from the companion star and this extra energy and matter helps ramp up the spin speeds to the mind boggling speeds they move.  According to the press release:

“This remnant is likely to be largely carbon and oxygen, because a star made of lighter elements like hydrogen and helium would be too big to fit the measured orbiting times,” said Dr Michael Keith (CSIRO), one of the research team members.

The density means that this material is certain to be crystalline: that is, a large part of the star may be similar to a diamond.”

The star stripped of its lighter elements was pushed into a further orbit by the gravity of the pulsar, since there is no fusion-able material left the star is classed as a planet. One that is ironically bigger than our own Sun.

One twitter user calculated that if it is a diamond then the value would be a whopping  £3.578×10^35… That is £357 million billion billion billion. More than the Gross domestic product…..of the EARTH

1 Press release http://www.eurekalert.org/pub_releases/2011-08/uom-apm082311.php