Tiny Pluto has a lot of followers. Being relegated to being a ‘dwarf planet’ from being a ‘planet’ has apparently not hurt Pluto’s chances of capturing a moon. It already has four moons, all of them tiny. Now, a fifth one has been discovered by the Hubble Space Telescope.
We covered the news of the discovery of the fourth moon of Pluto here and it was called P4. This new one has been provisionally christened S/2012(134340)1, but it already has gained the title ‘P5’. The other moons of Pluto are Charon (biggest), Nix and Hydra, apart from P4.
The announcement of the discovery came through Twitter when principal investigator in NASA’s New Horizons spacecraft Alan Stern said:
Just announced: Pluto has some company – We’ve discovered a 5th moon using the Hubble Space Telescope.
Oh, and the New Horizons spacecraft project plans to fly by Pluto in a bid to discover new horizons and study the dwarf planet. The launch is scheduled in 2015.
Difficult to see
Pluto and its moons are notoriously difficult to see. They tend to be blips of light, in the midst of a background made up of blips of light. The only difference is that the moons of Pluto go around Pluto, rather than the Sun, which the blips of light in the background do. The moons are quite small. Charon is the biggest, measuring about 1000 km across. The scale falls sharply with Nix and Hydra measuring about 80 km or lesser. P4 is about 30 km across.
It turns out that P5 is even smaller. It’s about 20 km across, but at places it measures less than 10 km, indicating that it is highly irregular. It was Hubble’s Wide Field Camera 3 which caught the 5th moon.
Many believe that Pluto might ‘capture’ planetary debris from their irregular orbits around the Sun and make them its moons.
NASA announced in a press release yesterday, that astronomers using Hubble’s wide field camera discovered a cluster of galaxies at the beginning stages of development. This is the farthest away that a cluster such as this has ever been observed in the early Universe. Michele Trenti, of the University of Colorado at Boulder and the Institute of Astronomy at the University of Cambridge in the United Kingdom, presented the results to the American Astronomical Society.
Early Cosmic Get-Together
Hubble was used to do a random sky survey when it came across these five small, but bright, galaxies clustered together in the farthest reaches of space. It is estimated that these galaxies were formed just 600 million years after the big bang. Clusters are the largest objects observed in our universe. They are usually comprised of hundreds of thousands of galaxies that are bound to each other by gravity. It’s sort of like a cosmic game of Pac-Man. These galaxies collide and swallow each other up to form larger galaxies. The galaxies observed in the image above are smaller than our own; however, they match ours in brightness.
“These galaxies formed during the earliest stages of galaxy assembly, when galaxies had just started to cluster together,” said Trenti. “The result confirms our theoretical understanding of the buildup of galaxy clusters. And, Hubble is just powerful enough to find the first examples of them at this distance.”
Long Distance Challenge
One of the biggest challenges is finding clusters bright enough to be seen 13 billion light-years away. Finding galaxy clusters this far back is challenging because they are so dim and scattered across the sky. Trenti expressed the need to examine many different areas as she said, “the search is hit and miss. Typically, a region has nothing, but if we hit the right spot, we can find multiple galaxies.”
Because the systems were so dim, the astronomers honed in on the brightest galaxies. The brighter the galaxy, the more mass it has which, in turn, marks a spot where cluster construction is most likely to occur. Astronomers use computer simulations to determine the way that these clusters likely formed. It is likely that there are many other galaxies in the same region that are just too dim to see. Based on the simulations, astronomers suspect that these bright galaxies form the central core of the cluster and will eventually form an elliptical giant similar to a closer cluster nearby, Virgo Cluster’s M87.
There is still some work to be done. The distances were measured based on color and the team will soon use spectroscopic observations, which measure the expansion of space. This will help astronomers precisely calculate the cluster’s distance and the velocity of the galaxies, which will show whether they are gravitationally bound to each other.
Researchers using NASA’s Spitzer and Hubble telescopes have discovered a galaxy burning brightly in the distant reaches of our universe. The galaxy, labeled GN-108036, appears to be giving birth to stars at an alarming rate. Using data from the Spitzer and Hubble telescopes, it is estimated the galaxy is churning out the equivalent of 100 of our suns per year. That is 30 times what the Milky Way galaxy produces. Seeing the galaxy is like looking back in time. It is believed to have appeared about 750 million years after the theoretical “Bing Bang”.
The international team of astronomers, led by Masami Ouchi of the University of Tokyo, Japan were the first to recognize the galaxy. They used the Subaru Telescope on Mauna Kea in Hawaii and later confirmed the distance using the W.M. Keck Observatory, which is located in Mauna Kea as well. Infrared readings from Spitzer and Hubble telescopes were crucial in determining star formations in the galaxy. The galaxy appears to be about 12.9 billion light-years away.
Astronomers use a measurement called “redshift” to measure the distance of stars. As light travels over great distances the wavelengths are stretched and become “redder” due the expansion of the universe. Objects with a larger “redshift” are more distant and further back in time. GN-108036 has a redshift of 7.2. To put this in perspective, very few galaxies have been discovered with a redshift of 7. Only two have been confirmed to be higher than GN-108036. It’s like looking at a cosmic time capsule.
What makes this such an amazing discovery is that the galaxy is so small yet it is producing a lot of stars. Galaxies that formed this early in time did not gather the mass that galaxies like our own have. GN-108036 was likely a player in a time called the “dark ages” of our universe. This was a time when shortly after the “Big Bang” a thick fog of hydrogen permeated the universe. As galaxies like GN-108036 formed, they essentially burned through the fog causing the barrier to become transparent. “This was therefore a likely ancestor of massive and evolved galaxies seen today,” said Bahram Mobasher, a team member from the University of California, Riverside.
There are monsters out there that are larger than anything we can imagine or know! This feeling was once again reaffirmed yesterday, when scientists published results that told them of two new supermassive blackholes that turn out to be bigger than any known so far. These two weigh in at an estimated 9.7 Billion Solar masses!
Supermassive blackholes are known to reside in the centers of galaxies. They are presumed to grow in size by gobbling up all matter and gases that come their way. The one at the center of our own Milky Way Galaxy is estimated at a million solar masses! If you think that is big, then be prepared to be blown away.
The largest known black hole was the Messier 87 black hole. This weighed in at a gigantic 6.3 billion solar masses. A new blackhole found in NGC 3842 in the Leo cluster is a gigantic 9.7 billion solar mass monster. This is located 320 million light years away from us. Another one has been found in NGC 4889, in the Coma cluster. This one is 335 million light years away and is similar in mass. The event horizon or the boundary beyond which nothing, not even light, can escape the gravitational force of the blackhole is bigger than the radius of the orbit of Pluto! Compare this to the Milky way blackhole, whose event horizon, by comparison, is a small one at just about one-fifth the size of the orbit of Mercury.
These blackholes are found by looking at the emission of the accretion disks. Matter falling in becomes so hot that it emits light in many wavelengths, including X-Ray and radio. Scientists know objects which are just about the size of a typical spiral galaxy, or even smaller, but emit radiation, which is unusually high. Such structures are called quasars’, shortened from Quasi-Stellar Objects. They are believed to be powered’ by a central blackhole engine!
The research is going to be published in Nature on 8th December.
Some great news is coming in from Washington! The James Webb Space Telescope (JWST) may just have got a new lease of life.
Money and relief
We reported that the JWST was cancelled (here) due to fund cuts by the US Senate Appropriations Sub-Committee. Yesterday (14th September), the US Senate Appropriations Committee met to discuss the details of the FY2012 (Financial Year 2012) bill and, surprise and glee, the JWST was sanctioned $530 million in 2012. This is a big improvement over the $374 million it was sanctioned in the last year.
This will be music to many ears, both intimately associated with the JWST project and other space enthusiasts. Hubble has been as much a darling for the public as for professional astronomers, and it would just be a shame if it had no successor. Losing the joy of watching deep space in high resolution, never knowing what one will find is a joy unparalleled! No one wants that to end.
Recently the James Webb Space Telescope completed a crucial phase in the construction of its mirrors. It has 21 mirrors, made up of 18 segments, forming one giant 21 foot mirror. The mirrors are the best in the world. They are made up of beryllium, so that they can withstand the near absolute zero temperature of space. They are also coated with a thin film of gold so that they are good reflectors of infra-red radiation. All of this goes into making JWST at least a 100x better than Hubble ever was.
Please note that JWST is not out of the woods yet! This is merely the money granted for 2012. The project will last till 2018 and there are still many hurdles ahead, especially for a project of this magnitude where the costs tend to swell up abruptly.
Apart from this grant to the JWST, NASA got a grant of $17.9 billion for the coming year. Although this is a $500 million reduction from the promised grant, it is still a hefty amount.
Hubble has done it again. It has captured a hitherto unknown fourth moon of Pluto, the dwarf planet. The three known moons of Pluto are Charon, Nix and Hydra. The fourth one, discovered just recently on 3rd July, 2011, and officially announced today by NASA and SETI, is temporarily known as P4.
Pluto was stripped of its planet tag on 24th August, 2006 and was relegated to the status of dwarf planet’ along with Eris and Ceres. Eris is, in fact, more massive than Pluto.
Charon is the most well-known moon of Pluto and was the only moon discovered till 2005. It is quite large, with a size comparable with Pluto. In 2005, two newer moons were discovered and named Nix and Hydra. It is not known whether this recently discovered moon, P4, was there at the time of the discovery of the previous moons or was captured more recently.
It was due to the wonder called the Hubble Space Telescope that a cold object, tiny in size and moving fast around a very distant body could be photographed. Mark Showalter of SETI Institute in Mountain View, California has this to say:
I find it remarkable that Hubble’s cameras enabled us to see such a tiny object so clearly from a distance of more than 3 billion miles (5 billion km).
The diameter of the new moon is just 8-21 miles, while Charon, by comparison, is a giant at 648 miles. Nix and Hydra are both about 50 miles in diameter.
NASA aims to discover more about the body least known to man with the upcoming New Horizons mission. New Horizons will hope to fly past Pluto in 2015, using inputs from Hubble’s photos to chart out its path.
Russia finally launched its giant radio telescope, the Spektr-R, into space using a Zenit rocket from the Baikonur Cosmodrome in Kazakhastan on the 18th July. No word about the operational status has been officially released.
The planned elliptic orbit has a perigee of 1000 km and apogee of 330,000 km. The observatory holds a giant 10 meter wide antenna and is expected to be a part of the International Radioastron Astronomy Project. The Astro Space Center of Moscow, a part of the Lebedev Physical Institute of the Russian Academy of Sciences, is coordinating the Radioastron mission. The project is a focal point of international co-operation with 20 nations contributing to it, including the United States.
Tricks up its giant sleeve
The claim to fame of this giant telescope is the facility of interferometry using ground based radio telescopes. In size, it is less than a tenth of the largest radio telescopes on Earth, but due to a technique called interferometry’, the telescope is expected to give resolution higher than Hubble in the radio frequencies.
Radio telescopes are laid out in a particular fashion on a wide area. They separately capture radio waves and then transmit this signal to a central computer, which adjusts for time delays and forms a coherent picture of what the entire field is seeing. This is done by adding’ or interfering’ the differing signals; thus the technique is called interferometry’.
Radio telescopes have another trick up their sleeve a Nobel Prize winning trick. They use the Earth’s rotation in increasing their effective aperture. Signals from a radio source are sampled from different baseline orientations that change as the Earth rotates. This data is then fed into a computer, which uses Fourier analysis in order to obtain information equivalent to a conventional telescope with the equivalent large aperture. This is what gives the name Aperture Synthesis’.
Radioastron will be hoping to use interference with numerous ground based telescopes in order to create a giant effective telescope. It hopes to have a resolution of 7 microarcseconds, which is more than 10,000 times the resolution of the Hubble Space Telescope. On the list of things that Radioastron plans to look at, is a black hole in the center of galaxy M87 (or Virgo A) and different pulsars.
Though this is not the first attempt at earth-space telescope interferometry the Japanese attempted such a thing with HALCA, 15 years ago this is certainly the biggest. This one blows even Hubble out of the water.
With the end of the space shuttle program, NASA wants to erase out its legacy. This seems to be the mood, one of disbelief, desperation and anger, in the astronomy circles, in reaction to the cancellation of the James Webb Space Telescope (JWST) program. The JWST, named after the former NASA administrator, is slated to be the successor of the Hubble Space Telescope.
The hue-and-cry follows after the House Appropriations subcommittee decided to slash NASA’s budget for the 2012 fiscal year by nearly 9%, relegating it to its 2008 budget figures. The revised funding of $16.8 billion is a flat $1.6 billion less than the 2011 figure and $2.0 billion less than President Obama’s recommendation to the subcommittee for NASA in 2012.
The JWST project, currently billed at $6.5 billion, is $1.5 billion over its proposed budget. The project is beset with problems, typical of any such massive pioneering venture budget overruns, design overhauls and repeated failures to meet set deadlines. Apparently, the subcommittee thought enough was enough.
The JWST was set to be the best eye in space, surpassing both the Hubble Space Telescope and the Spitzer in its ability to gaze deeper into space and farther back in time. It is a dedicated Infrared Telescope, enabling it to peer through the cold and thick dust clouds that remain opaque in the visible wavelength regime. At about 100 times the magnification power of the Hubble, it was set to make Hubble look like a pair of binoculars. Debra Elmegreen, president of the American Astronomical Society says,
It has the potential to transform astronomy even more than the Hubble Space Telescope did, and it will serve thousands of astronomers in the decades ahead. We cannot abandon it now.
The JWST was slated for a 2014 launch, but was later slotted for a more realistic 2015 launch. Now, no one knows…
Even though scientists are up-in-arms against the cancellation, dissenting voices are emerging. Our own senior editor, Clif Sipe, makes a pertinent point
I think the days of huge government programs are over for several years. The entire European and US economies are in trouble, and might be for some time. When I hear scientists complaining about it, I understand, but I have seen fellow employees at work, being sent to the unemployment lines. That puts things in real perspective for me … most scientists will not lack for work.
However, others are not so sympathetic. Dan Weaver (@DanWeaver_) says on Twitter:
Canceling James Webb space telescope b/c it’s over budget? US politicians should apply that logic to real budget drains: Iraq & Afghanistan
Maybe there is a grain of truth in that. True, jobs and livelihood problems of people are important, but these problems have persisted in American society, and, indeed, of all societies around the world, for centuries. Isn’t it unique that a 20 year expedition by the most successful scientific device ever built the Hubble Space Telescope be followed up by the grandeur of the JWST?
The internet has been buzzing. Here’s a petition, open to only US citizens appealing for the restoration of the JWST project. The Facebook page for saving the James Webb Telescope is here. Twitter is overflowing with tweets about the JWST. Use any of the following tags – #SaveThisTelescope, #JWST or #saveJWST for your tweets or search.
Its indeed sad, but true, that fulfilment of the long standing desire to know the stars doesn’t come cheap.
If the Cosmos is the place of all things beautiful and unusual, the Hubble Space telescope (known simply as Hubble’ or HST) is the ultimate eye to see it with. Launched on 20th April, 1990, aboard the Discovery space shuttle by NASA, as the best of the space-based optical telescopes, Hubble has reached out to all.
Hubble’s images have filled the hard disks of active researchers and eager school students alike, and these have endeared the large floating eye in space to millions worldwide. It has captured stunning, but violent galaxy collisions, seen never-before seen nebular formations, glimpsed the merging of galactic black holes and captured the awe-inspiring and data rich alleys of star-forming nurseries, all the while enthralling us and challenging our own perception of the vastness of the universe. In fact, the word Hubble’ today bears more resonance with the telescope rather than the famed astronomer, Edwin Hubble, after whom it is named.
Hubble also happens to be the only telescope that was serviced by astronauts in space. When Hubble started acquiring images, a flaw was found in the positioning of the main mirror. A collective sigh and gasp throughout the astronomy fraternity around the world was followed by a daring and successful mission by NASA technicians, which involved them going into space and correcting the incorrect alignment of the main mirror. Hubble has never looked back since.
Enjoy the brilliant images below (they may take a second to load). Don’t forget to wish a very Happy Birthday to Hubble. To get more, click here.
Astronomers released this brilliant new snap by Hubble in order to celebrate its 21st birthday. (Go to link for a bigger image!)
Hubble is supposed to function till 2014, after which its successor the James Webb Space Telescope is expected to take over.
I expect a few moist eyes when Hubble is finally plunged into the ocean. I know that my eyes will be wet.
The cosmos is a mysterious place, but we know a surprising lot about it. The knowledge, known as astronomy’, has been primarily acquired through observing the skies night after night, year after year. People used their eyes as the instrument of observation for a long time, but the problem is that the opening of the eye, called the pupil, is just too small – about one-eighths of an inch across. Very little light gets through and thus dim cosmic objects are invisible to the naked eye. For progress, we needed bigger apertures with which we could collect light and something which could automatically record images of the night sky. It turns out that a bigger aperture emerged long before the recording instruments.
One facet: ‘We need a bigger aperture’
A telescope is just a bigger and simpler version of the eye. Light falls on an opening, called the aperture, and is then focused onto a smaller opening, called the eye-piece, for a person to look through. Telescopes are basically of two types the reflecting ones and the refracting ones.
The main aim is to maximize the aperture for greater collection of light. This is easier in case of reflecting telescopes than for refracting telescopes. The problem is that a bigger aperture needs a bigger lens. Lenses tend to get heavy as they become bigger. Not only that, they tend to sag under their own weights. For a reflecting telescope, a bigger aperture does require a bigger reflecting mirror, but that is much less of a problem. This is the reason why reflecting telescopes have taken over. All large optical telescopes today are reflecting ones.
Examples of really large modern optical telescopes are the KECK and the SALT. The most successful of all telescopes is, of course, the Hubble Space Telescope.
Another facet: ‘We need a large telescope in space’
The fact that a lot of radiation doesn’t reach the earth’s surface is a major stumbling block to observations in wavelength regions in the electromagnetic spectrum, other than optical. The following image explains this phenomenon the best. Note the wavelength regions that do reach and those that don’t.
Thus, it is impossible to build a ground based gamma or x-ray telescope as long as we have an atmosphere. The only option is to send the telescope off into space. The Chandra X-Ray Telescope is the best of the x-ray telescopes.
The atmosphere creates problems even for the optical band of radiation. Air movements and thermal effects create density gradients both locally and globally in the atmosphere. These distort the passage of optical light – an aberration called ‘seeing’. Hence the Hubble Space Telescope was a necessity rather than a luxury, and how it has proved itself!
Radio is a region where a lot of observation has been done. Radio Telescopes are easy to build and radio is not attenuated by the atmosphere. By using certain specialized techniques, very accurate information can be found. Often cosmic structures have regions where the gas and dust density is so high that optical and even X-rays are absorbed. These optically opaque regions are conveniently observed in the radio band.
Advanced imaging techniques have greatly improved on the amount of information we can obtain from an observation. Advances in solid state physics have allowed us to create excellent image reproduction devices like CCD’s and CMOS. One thing is for sure once man had looked up and seen the cosmic wonders, he was sure to get addicted to it.