Navigation of Mars Science Laboratory to Mars

November 24, 2011 By Nancy Atkinson, Universe Today

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Getting the Mars Science Laboratory to the Red Planet isn’t as easy as just strapping the rover on an Atlas V rocket and blasting it in the general direction of Mars. Spacecraft navigation is a very precise and constant science, and in simplest terms, it entails determining where the spacecraft is at all times and keeping it on course to the desired destination.

And, says MSL navigation team chief Tomas Martin-Mur, the only way to accurately get the Curiosity rover to Mars is for the spacecraft to constantly be looking in the rearview mirror at Earth.

“What we do is ‘drive’ the spacecraft using data from the Deep Space Network,” Martin–Mur told Universe Today. “If you think about it, we never see Mars. We don’t have an optical navigation camera or any other instruments to be able to see or sense Mars. We are heading to Mars, all the while looking back to Earth, and with measurements from the Earth we are able to get to Mars with a very high accuracy.”

This high accuracy is very important because MSL is using a new entry, descent and landing guidance system which will allow the spacecraft to land more precisely than any previous landers or rovers.

“It is very challenging, and even though it is something similar to what we have done before with the Mars Exploration Rover (MER) mission, this time it will be done at an even higher level of precision,” Martin-Mur said. “That allows us to get to a very exciting place, Gale Crater.”

On Earth, we constantly can find exactly where we are with GPS – which is on our cell phones and navigation equipment. But there is no GPS at Mars, so the only way the rover will be able to head to –and through — a precise point in the Red Planet’s atmosphere is for the navigation team to know exactly where it the spacecraft is and for them to keep telling the spacecraft exactly where it is. They use the Deep Space Network (DSN) for those determinations from launch, all the way to Mars.

The Deep Space Network consists of a network of extremely sensitive deep space communications antennas at three locations: Goldstone, California; Madrid, Spain; and Canberra, Australia. The strategic placement approximately 120 degrees apart on Earth’s surface allows constant observation of spacecraft as the Earth rotates. 

But of course, it’s not as easy as just getting the rocket from Point A to Point B since Earth and Mars are not fixed positions in space. Navigators must meet the challenges of calculating the exact speeds and orientations of a rotating Earth, a rotating Mars, as well as a moving, spinning spacecraft, while all are simultaneously traveling in their own orbits around the Sun.

There are other factors like solar radiation pressure and thruster firings that all have to be precisely calculated.

Martin-Mur said even though MSL is a much bigger rover with a bigger spacecraft and backshell than the MER mission, the navigation tools and calculations aren’t much different. And in some ways, navigating MSL might be easier.

“The Atlas V vehicle provides a much more precise launching and can put us in a more precise path than the MER, which used a Delta II,’ Martin-Mur said. “This allows us to use less propellant, proportionally per pound, to get to Mars than the MER rovers did.”

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The MSL Entry, Descent and Landing Instrument (the black box in the middle left of the photo) is scheduled to launch as part of the Mars Science Laboratory mission. Credit: NASA

The MER rovers and spacecraft weighed about 1 ton, while MSL weighs almost 4 tons. MSL is allotted 70 kg of propellant for the cruise stage, while the MER rovers each used about 42 kg of propellant.

Interestingly, for the MSL spacecraft to descend through Mars’ atmosphere and land, the spacecraft will use about 400 kg of propellant.

Additionally, Martin-Mur said more precise planetary ephemeris and Very Long Baseline Interferometry measurements are available, enabling the navigation to be able to deliver the spacecraft to the right place in the atmospheric entry interface, so the vehicle finds itself in the range of parameters that it has been designed to operate.

Navigation at Launch

It all starts with years of preparations and calculations by the navigation team, which must calculate all the possible trajectories to Mars depending on exactly when the Atlas V rocket launches with MSL aboard.

In some cases there are literally thousands of launch opportunities and all the possible trajectories must be calculated precisely. The Juno mission, for example, had two-hour daily launch windows with 3,300 possible launch opportunities. For MSL the daily launch windows contain liftoff opportunities in 5 minutes increments. Across the 24 day launch period the team has calculated 489 different trajectories for all the possible launch opportunities.

But ultimately, they will end up using only one.

“This is not something you do on the fly – you prepare all this well in advance so you have time to sit back and assess it and check it,” said another member of the MSL navigation team, Neil Mottinger, who has worked at the Jet Propulsion Laboratory since 1967. He’s worked on navigation for many missions like Mariner, Voyager, the MER, and several international missions.

“The initial function of navigation at launch is to determine the actual spacecraft trajectory well enough so the spacecraft signal will be well within the beam-width of the DSN antennae,” Mottinger told Universe Today.

The Mars Science Laboratory will separate from the rocket that boosted it toward Mars at about 44 minutes after launch, with the navigator’s tracking the spacecraft’s every move.

Mottinger added that without the DSN’s communication capabilities, there are no planetary missions. “The Navigation team does whatever it can to make sure there aren’t any gaps in communication,” he said. “It’s crunch time during the first 6-8 hours after launch to be able to determine the exact position of the spacecraft.”

From the recent problems with the Phobos-Grunt mission, it is evident how difficult it is to track and communicate with a just-launched spacecraft.

Mid-course Corrections

Again, the navigation team has modeled and calculated all the maneuvers and thruster burns for the mission. Once MSL is on its way to Mars, the navigation team will revisit all their models and design the maneuvers to take the spacecraft to the right entry interface at Mars.

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Powered Descent, Sky Crane & Flyaway for MSL. Credit: NASA/JPL

“We’ll keep doing orbit determination and re-designing the maneuvers for the spacecraft,” said Martin-Mur. “MSL has 1 lb thrusters – the same size as the MER spacecraft — but our spacecraft is almost four times heavier so the maneuvers we do take a long time – some will take hours.”

For interplanetary navigation, the engineers use distant quasars as landmarks in space for reference of where the spacecraft is. Qusars are incredibly bright, but are at such colossal distances that they don’t move in the sky like nearer background stars do. Martin-Mur provided a list of nearly 100 different quasars that could be used for this purpose, depending on where the spacecraft is.

“It is interesting,” Martin-Mur mused, “with quasars we are using something that is billions of light years away from us, from the very early universe, which are so old that they might not even be there anymore. It is really cool that we are using an object that currently may not exist anymore, but using them for very precise navigation.”

The navigation team also needs to model the solar radiation pressure – the affect the Sun’s radiation has on the spacecraft.

“We know very well, thanks to our friends from the Solar Systems Dynamics group, where Mars is going to be and where the Earth and Sun are,” said Martin-Mur. “But since this spacecraft has not been in space before, what is not known precisely is how solar radiation pressure will affect the surface properties of the spacecraft, and how it will perturb the spacecraft. If we don’t have a good model for that, we could be hundreds of kilometers off as the spacecraft goes from Earth to Mars.”

Arriving at Mars

As the spacecraft approaches Mars, it is very important to know precisely where the spacecraft is. “We need to target the spacecraft to the right entry point,” said Martin-Mur, “and tell the spacecraft where it will enter, so it will be able to find its way to the landing site.”

The MSL Entry Descent and Landing Instrumentation, or MEDLI, will stream information back to Earth as the probe enters the atmosphere, letting the navigators — and the science team – know precisely where the rover has landed.

Only then will the navigation team be able — maybe — to breathe a sigh of relief. 

Source: Universe Today

Physicists: Did neutrinos break the speed of light?

November 23, 2011 By Linda B. Glaser

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Professors of Physics Julia Thom-Levy and Eanna Flanagan prepare for an open discussion in Clark Hall about recent experimental results that suggest that neutrinos may travel faster than the speed of light. Photo: Lindsay France

The revolutionary news that an experiment measured particles traveling faster than the speed of light drew varied ages and backgrounds to a standing-room only physics department forum, "Faster Than the Speed of Light?," in Clark Hall at the Cornell University Nov. 17.

The experiment that triggered the excitement was simple: Scientists at theCERN accelerator in Switzerland fired a beam of neutrinos 730 kilometers through the mountains to the underground Gran Sasso Laboratory in Italy and its enormous OPERA neutrino detector.

Neutrinos are expected to travel extremely close to the speed of light and would make it to Gran Sasso in 2.4 milliseconds, the time it takes a fly to flap its wings once, said Julia Thom-Levy, assistant professor of physics -- but the observation showed that they were 60 nanoseconds faster than light could have traveled.

Researchers calculated the speed by measuring the time difference between the neutrinos' departure from CERN and their detection in OPERA, with an accuracy within 1 nanosecond. Experimenters used a GPS satellite system, refined with Cesium clocks, for the timing, a procedure that is also used inradio astronomy.

But working with neutrinos is extremely difficult. Independent experimental confirmation is needed and will be provided by a similar neutrino experimentin the United States over the next few years. If OPERA's observation of neutrino speed is correct, said physics professor Eanna Flanagan, it presages a physics revolution and requires a new theoretical framework.

In the two months since the OPERA results were posted on the scientific database arXiv, more than 100 papers have offered explanations. But none of them satisfied physics professor Yuval Grossman. "Physics becomes more compact and more beautiful as we unify forces, and these explanations would make physics uglier," he said.

However, Grossman noted that while the commonly held understanding is that no object can travel faster than the speed of light in a vacuum (186,282 miles per second), what general relativity actually says is that there is a maximum velocity beyond which nothing can go. Since nothing has ever out-raced light, its speed has been assumed to be the maximum possible velocity. But what if neutrinos are faster? 

"The laws of physics wouldn't change, only the universal constant," said Grossman.

One of the strongest arguments against OPERA's results is their conflict with the measurement of neutrinos emitted by Supernova 1987A. If neutrinos really traveled faster than the speed of light, the supernova's neutrinos should have arrived in 1983, not 1987.

But as one audience member pointed out, perhaps they did arrive in 1983 and no one noticed. Or perhaps the discrepancy of results is because OPERA's neutrinos traveled through solid rock, not the vacuum of space.

Still, while some current theories, such as those suggesting extra dimensions, might be able to incorporate neutrinos going faster than the speed of light, Grossman contended that they couldn't explain the amount of speed seen with OPERA.

Last month, OPERA researchers repeated the experiment with shorter neutrino bursts to eliminate one possible cause of experimental error; theneutrinos still arrived faster than they should have. The researchers subsequently submitted their paper to the peer-reviewed Journal of High Energy Physics. After the forum, many of the more than 150 attendees lingered, talking enthusiastically in small groups. Because despite all the reasons OPERA's results could be wrong, as one audience member said, "inphysics, we never say we know anything absolutely because although it might have a low probability, that probability is not zero."

Provided by Cornell University 

Scientists solve mystery of the eye

November 17, 2011 by Lisa Zyga 

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A schematic representation of 7-cis- (PSB7, green), 9-cis- (PSB9, blue), 11-cis- (PSB11, black), 13-cis- (PSB13, purple), and all-trans-retinal (PSBT, red). PSB stands for “protonated Schiff base,” the linkage between the retinal chromophore and the opsin protein. Image credit: Sekharan and Morokuma. ©2011 American Chemical Society

Scientists have a good overall understanding of human vision: when light enters our eyes, it is focused by the lens and strikes the retina in the back of the eye. The light causes some of the millions of photoreceptor cells that line the retina to undergo a chemical change, which send a message through the optic nerve fiber to the brain, which creates a picture. However, there are still a few unresolved questions in the details of the vision process, one of which is why the eye evolved to use a certain light-absorbing chromophore called 11-cis-retinal instead of one of its isomers (i.e., molecules with the same atoms but in different arrangements), such as 7-cis, 9-cis, or 13-cis.

Chemists Sivakumar Sekharan from Emory University in Atlanta, Georgia, and Keiji Morokuma from Emory University and Kyoto University in Kyoto, Japan, describe the eye’s use of 11-cis-retinal as “one of the basic and unresolved puzzles in the chemistry of vision.” But by taking advantage of the rapid advances in hybrid quantum mechanics/molecular mechanics (QM/MM) computational modeling, the researchers have found that the answer to this puzzle lies in electrostatic interactions in the retina. Their study is published in a recent issue of the Journal of the American Chemical Society.

The retina contains light-sensitive photoreceptor cells known as rods and cones, which convert incoming light into electrical impulses that are sent to the brain. On the top of every rod and cone is a region that contains opsin proteins bound to 11-cis-retinal chromophores, which together are called rhodopsin. When light strikes the retina, the 11-cis-retinal chromophores absorb the light, which causes them to undergo an isomerization and change their molecular configuration from 11-cis-retinal to all-trans-retinal in a matter of picoseconds. The difference between these two isomers involves the positions of the hydrogen atoms, a shape change that causes the opsin protein to change shape in response. The opsin shape change, in turn, leads to a cascade of biochemical reactions in the photoreceptor cell that ultimately generate an electrical impulse.

Since the 11-cis-retinal is the retina’s first responder to incoming light, its unique geometric configuration clearly plays an important role in the vision process. However, theoretically there are a handful of other retinal isomers that seem capable of performing this task, yet for some reason photoreceptor cells only function with 11-cis-retinal (and the corresponding 11-cis-rhodopsin). 

“Because the primary event in vision involves no breaking of chemical bonds but only a conformational change in the shape of the molecule from bent cisto the distorted all-trans form, scientists wondered why 7-cis-, 9-cis- or 13-cis- isomers could not achieve this goal,” Sekharan told PhysOrg.com.

To answer this question, the researchers built computational models of the rhodopsin found in the eyes of cows, monkeys, and squids. While all known animals’ eyes use 11-cis-retinal, the opsin in different animals contains different numbers and positions of amino acids. Using a cutting-edge QM/MM modeling method called ONIOM (Our own N-layered Integrated Molecular Orbital), the researchers prepared models that matched different animals’ opsins with 7-cis, 9-cis, 11-cis, and 13-cis molecules serving as chromophores. In these artificial rhodopsins, the researchers analyzed the structure, stability, energetics, and spectroscopy to try to find out what makes 11-cis-retinal nature’s preferred isomer.

The results of the modeling showed that differences in the electrostatic interactions between the opsin protein and the retinal chromophore played the biggest factor in the natural selection of 11-cis-retinal over the other cisisomers. Due to electric charges, the link between 11-cis-retinal and opsin has a higher stability than the links between other cis isomers and opsin, making it the most favorable choice.

“Our results show that the strong electrostatic interaction between retinal and opsin favors the natural selection of 11-cis- over other cis-isomers and arguably prepares the chromophore for the upcoming photochemical event,” Sekharan said. “This indeed is very surprising given the fact that, outside the protein environment, 11-cis-retinal is one of the least stable isomers. Apparently, our results on cow, monkey and squid demonstrate that organisms everywhere may tend to gravitate towards common selection.”

Sekharan added that the results not only provide a better understanding of the eyes on a molecular level, but could also have applications for artificial retinas.

“Because rhodopsin serves as a decisive crossing point between an organism and its environment, we have been always impressed with this interesting interface by seeing it, say, from the outside and not from the inside,” he said. “Using the ONIOM-QM/MM method we developed, we can ‘enter’ deep into the dark side of this fascinating molecule. One of interesting findings to emerge out of our investigation is that 9-cis-retinal is only slightly higher in energy compared to 11-cis-retinal. This provides strong evidence for the presence of 9-cis-rhodopsin in nature, which in turn may well aid in optimizing the parameters required for designing artificial retinas.”

More information: Sivakumar Sekharan and Keiji Morokuma. “Why 11-cis-Retinal? Why Not 7-cis-, 9-cis-, or 13-cis-Retinal in the Eye?” Journal of the American Chemical Society. DOI:10.1021/ja208789h

Copyright 2011 PhysOrg.com.

Nudity tunes up the brain

November 17, 2011

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Amplitude of early visual brain responses ("N170" response) to different types of pictures showing human bodies. The bars represent how much stronger the responses evoked by body pictures were in comparison to control pictures showing cars.

Researchers at the University of Tampere and the Aalto University, Finland, have shown that the perception of nude bodies is boosted at an early stage of visual processing.

Most people like to look at pictures of nude or scantily clad human bodies. Looking at nude bodies is sexually arousing, and a nude human body is a classic subject in art. Advertising, too, has harnessed half-clothed models to evoke positive images about the products advertised. Brain imaging studies have localized areas in the brain which are specialized in detecting human bodies in the environment, but so far it has been unknown whether the brain processes nude and clothed bodies in different ways.

Researchers at the University of Tampere and the Aalto University, Finland, have now shown that the perception of nude bodies is boosted at an early stage of visual processing.

In the study, participants were shown pictures of men and women in which the models wore either normal everyday clothes or swimsuits, or were nude. At the same time, visual brain responses were recorded from the participants' electrical brain activity. This method allows researchers to investigate the early stages ofvisual information processing.

The results showed that, in less than 0.2 seconds, the brain processes pictures of nude bodies more efficiently than pictures of clothed bodies. In fact, the less clothing the models in the pictures were wearing, the more enhanced was the information processing: the brain responses were the strongest when the participants looked at pictures of nude bodies, the second strongest to bodies in swimsuits, and the weakest to fully clothed bodies. Male participants' brain responses were stronger to nude female than to nude male bodies, whereas the female participants' brain responses were not affected by the sex of the bodies.

The results show that the brain boosts the processing of sexually arousing signals. In addition to the brain responses, the participants' self-evaluations and measurements reflecting the activation of the autonomic nervous system were in line with expectations, showing that nude pictures were more arousing than the other types of pictures. Such fast processing of sexual signals may play a role in reproduction, and it ensures efficient perception of potential mating partners in the environment.

More information: Hietanen JK, Nummenmaa L, 2011 The Naked Truth: The Face and Body Sensitive N170 Response Is Enhanced for Nude Bodies. PLoS ONE 6(11): e24408. doi:10.1371/journal.pone.0024408

Provided by Academy of Finland

61 whales die in New Zealand mass stranding

November 16, 2011

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This handout photo taken on February 20, 2011 by New Zealand's Department of Conservation shows pilot whales stranded on a remote beach on Stewart Island. More than 60 pilot whales died in a mass stranding at a remote New Zealand beach, conservation officials said Wednesday.

More than 60 pilot whales died in a mass stranding at a remote New Zealand beach, conservation officials said Wednesday.

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Tourists found the pod of 61 beached whales on Monday at Farewell Spit, on the top of the South Island, the Department of Conservation (DOC) said.

DOC local manager John Mason said a large number were already dead and hopes the survivors would refloat at high tide on Tuesday were dashed when the whales swam back to shore.

He said 18 whales remained alive early Wednesday and DOC staff decided to euthanize them, rather than prolong their suffering.

"It's the worst outcome and it's not a job our staff enjoy doing at all," Mason said.

Pilot whales up to six metres (20 feet) long are the most common species of whale in New Zealand waters, with mass standings occurring about two or three times a year.

Scientists are unsure why pilot whales beach themselves, although they speculate it may occur when their sonar becomes scrambled in shallow water or when a sick member of the pod heads for shore and others follow.

(c) 2011 AFP

Russian spacecraft delivers new crew to ISS

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US astronaut Dan Burbank (C) with Russian cosmonaut Anton Shkaplerov (L) and Anatoly Ivanishin (R) at Russia's Baikonur cosmodrome on November 14. A Soyuz spacecraft carrying Burbank, Shkaplerov and Ivanishin docked Wednesday at the International Space Station in the first Russian manned mission for five months after a spate of technical failures.

A spacecraft carrying two Russians and an American docked Wednesday with the International Space Station in the first Russian manned mission for five months after a spate of technical failures.

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The glitch-free docking of the Soyuz TMA-22 came after a textbook launch on Monday and was a huge boost to Russia which postponed the mission in the wake of the disastrous crash of an unmanned supply ship bound for the ISS in August.

"The ship docked at 09:24 Moscow time (0524 GMT). Everything went ahead normally," a Russian space agency spokesman told AFP.

"The process of the approach and docking was carried out in an automatic regime under the supervision of mission control centre and the crew," Russia's flight control centre outside Moscow said in a statement on its website.

The capsule was carrying American Dan Burbank and Russians Anton Shkaplerov and Anatoly Ivanishin, who joined the three crew currently on board the ISSS.

The current ISS crew of American Mike Fossum, Japan's Satoshi Furukawa and Russia's Sergei Volkov will return to Earth on November 22 and a new crew will head up from Baikonur on December 21.

The Soyuz crew opened the hatch at 11.39 am Moscow time (0739 GMT), NASA said. Its website showed footage of the smiling astronauts floating in through the narrow hatch from the Soyuz to hugs from their colleagues.

The men were set to enjoy their first meal together and then the new crewmates were to sleep to reset their body clocks.

"I'm glad finally to get aboard," Burbank said via a video link with mission control, aired on NASA's website. "It was a great ride up here and it's going to be a great stay."

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Russia's Soyuz TMA-22 spacecraft on a launch pad at Russia's Baikonur cosmodrome on November 14. The glitch-free docking of the Soyuz TMA-22 came after a textbook launch on Monday and was a huge boost to Russia which postponed the mission in the wake of the disastrous crash of an unmanned supply ship bound for the ISS in August.

Burbank is a veteran of two US shuttle missions to the ISS, while Shkaplerov and Ivanishin were making their first space flight.

The men were accompanied by the maggots of fruit flies, which they will use for experiments to test for any mutations linked to spending time in space.

The crew blasted off from the Baikonur cosmodrome in Kazakhstan on Monday in Russia's first manned mission since June. The workhorse rockets had been grounded after the unmanned Progress supply ship crashed in August.

The Soyuz-U rocket that failed to take the Progress to orbit is closely related to the Soyuz-FG that is used for manned launches, prompting the temporary grounding of the entire arsenal of the Soyuz rockets. 

The failed launch of the Progress cargo ship eroded faith in Russia's status as a space superpower just as it had become the only nation capable of taking humans to the ISS after the retirement of the US shuttle in July.

It also forced a complete rejig of staffing for the ISS. The latest mission had been due to go up in September.

The Progress mishap was just the worst in a string of embarrassing technical failures with the Russian space programme.

As well as the Progress and possibly the Phobos-Grunt Mars probe, Russia has lost three navigation satellites, an advanced military satellite and a telecommunications satellite due to faulty launches in the past 12 months.

Phobos-Grunt was launched on November 9 on a mission to take a soil sample from a Martian moon but has failed to head out of Earth's orbit on its course to the red planet.

The recent problems were a major disappointment for Russia in the year marking half a century since Yuri Gagarin made man's first voyage into space from the same historic cosmodrome.

Yet the head of the Russian space agency, Vladimir Popovkin told the astronauts via satellite link that "We never doubted that the technology would work normally" in taking their capsule to the ISS.

The Soyuz rocket design first flew in the late 1960s and has a proud safety record, with Russia boasting that its simplicity has allowed it to outlive the shuttle.

Whereas NASA endured the fatal loss of the Challenger and Columbia shuttles in 1986 and 2003, Moscow has not suffered a fatality in space since the crew of Soyuz-11 died in 1971 in their capsule when returning to Earth.

(c) 2011 AFP

Happy birthday, Sir William Herschel!

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On this day in 1738, an astronomy legend was born – Sir William Herschel. Among this British astronomer and musician’s many accomplishments, Herschel was credited with the discovery of the planet Uranus in 1781; detecting the motion of the Sun in the Milky Way in 1785; finding Castor’s binary companion in 1804 – and he was the first to record infrared radiation. Herschel was well known as the discoverer of many clusters, nebulae, and galaxies. This came through his countless nights studying the sky and writing catalogs whose information we still use today. Let’s take a brief, closer look at just who he was…

His son, John Herschel, would carry on in his father’s footsteps and also became a famous astronomer. While few of us will ever be able to match Herschel’s passion for astronomy, at least we can take a moment to look at the stars and wish this astronomy “great” a very happy birthday!

Born as Frederick William Herschel, this Hanover, Germany native had nine brothers and sisters. During his teenage years, he and his brother, Jakob, were oboists in a military band. When war ensued, his father sent the pair to England to escape. Once there, Herschel continued his musical career by playing cello and harpsichord – eventually composing 24 symphonies, a handful of concertos and religious music. He continued to be a musician, with many appointments, until middle age. Most of his family also migrated to England, the most famous of which is his sister Caroline, who came to live with him in 1772.

But it wasn’t music that was Herschel’s passion. After he met English Astronomer Royal Nevil Maskelyne, he began construction on his own reflector telescope, spending up to 16 hours a day grinding and polishing the speculum metal primary mirrors. By age 35 he’d begun his astronomical journey in earnest – and a year later he began recording his observations from the Great Orion Nebula to the rings of Saturn. Sir William’s interest was taken by the study of double stars and with a 160mm telescope of his own construction, he began a systematic search for binaries among “every star in the Heavens” in October, 1779 and continued listing discoveries through 1792, eventually compiling three catalogs.

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During this time he continued to support himself and his sister with his music. In her biography, Caroline recounts how he would rush home between acts to scan the skies – and how she often had to clean pitch from mirror-making from his clothes to make him presentable. From 1782 to 1802, Sir William swept the skies, recording all he saw and sharing his discoveries with other astronomers. So devoted was he, that he even gave Caroline her own telescope in 1783, encouraging her to also make her own observations and discoveries. Herschel published his discoveries as three catalogues, a walloping 2400 entries, filled with distant nebulae and cosmic wonders. Over the time of his astronomical career, Herschel constructed more than four hundred telescopes – the most famous of which had an almost 50 inch diameter mirror and a 40 foot focal length! 

In later years, he and Caroline moved on to Windsor Road in Slough… a residence which would eventually be come to known as “Observatory House”. It was during this time he married and eventually had a son – John. Caroline also moved on, yet continued to be his secretarial assistant. Sir William’s astronomical career was quite illustrious – so much so that this article only highlights a few of his accomplishments. He observed and recorded the satellites of his discovery, Uranus, along with more obscure moons belonging to Saturn. He did work with infrared radiation, popularized the term “asteroid”, studied the martian polar caps – revealing them as seasonal – and may very well have been the first to discover the rings of Uranus. His lack of a formal “astronomical education” never slowed Sir William Herschel down!

“I have looked further into space than ever human being did before me. I have observed stars of which the light, it can be proved, must take two million years to reach the Earth.”

Herschel’s life ended at a ripe old age of 84… Passing on at his beloved Observatory House. His son, John Herschel, would carry on in his father’s footsteps and also became a famous astronomer. While few of us will ever be able to match Herschel’s passion for astronomy, at least we can take a moment to look at the stars and wish this astronomy “great” a very happy birthday!

Source: Universe Today

James Herschel and Bangalore - James Herschel was an ICS officer and was with British Survey, he is credited with setting up of Observatory at High Grounds now known as Jawaharlal Nehru Planetarium 

Sir William James Herschel, 2nd Baronet (9 January 1833 – 24 October 1917)^[1] was a British officer in India who used fingerprints for identification on contracts.^[1][2][3] He was born in Slough in Buckinghamshire (now Berkshire), a son of the astronomer, John Herschel. He lived at Warfield in Berkshire.

Herschel is credited with being the first European to note the value of fingerprints for identification. He recognized that fingerprints were unique and permanent. Herschel documented his own fingerprints over his lifetime to prove permanence. He was also credited with being the first person to use fingerprints in a practical manner. As early as the 1850s, working as a British officer for the Indian Civil Service in the Bengal region of India, he started putting fingerprints on contracts.^[1]

In 1858, Herschel used whole handprints as a signature on contracts, following theIndian Rebellion of 1857, which changed Bengal directly to British control (the British Raj, ending control by the British East India Company). Rajyadhar Konai was one of the first people Herschel fingerprinted as a means of identification.^[2]