Universe Today

August 29, 2007December 26, 2015 by Nancy Atkinson

A Submarine for Europa

Many planetary scientists believe that Jupiter’s moon Europa is our solar system’s best contender to share Earth’s distinction of harboring life. Evidence gathered by the Voyager and Galileo spacecrafts suggests Europa contains a deep, possibly warm ocean of salty water under an outer shell of fissured ice. In a paper published in the July 2007 Journal of Aerospace Engineering a British mechanical engineer proposes sending a submarine to explore Europa’s oceans.

Carl T. F. Ross, a professor at the University of Portsmouth in England offers an abstract design of an underwater craft built of a metal matrix composite. He also provides suggestions for suitable power supplies, communication techniques and propulsion systems for such a vessel in his paper, “Conceptual Design of a Submarine to Explore Europa’s Oceans.”

Ross’s paper weighs the options for constructing a submarine capable of withstanding the undoubtedly high pressure within Europa’s deep oceans. Scientists believe that this moon’s oceans could be up to 100 kilometers deep, more than ten times deeper than Earth’s oceans. Ross proposes a 3 meter long cylindrical sub with an internal diameter of 1 meter. He believes that steel or titanium, while strong enough to withstand the hydrostatic pressure, would be unsuitable as the vessel would have no reserve buoyancy. Therefore, the sub would sink like a rock to the bottom of the ocean. A metal matrix or ceramic composite would offer the best combination of strength and buoyancy.

Ross favors a fuel cell for power, which will be needed for propulsion, communications and scientific equipment, but notes that technological advances in the ensuing years may provide better sources for power.

Ross concedes that a submarine mission to Europa won’t occur for at least 15-20 years. Planetary scientist William B. McKinnon agrees.

“It is difficult enough, and expensive, to get back to Europa with an orbiter, much less imagine a landing or an ocean entry,” said McKinnon, professor of Earth and Planetary Sciences at Washington University in St. Louis, Missouri. “Sometime in the future, and after we have determined the ice shell thickness, we can begin to seriously address the engineering challenges. For now, it might be best to search for those places where the ocean has come to us. That is, sites of recent eruptions on Europa’s surface, whose compositions can be determined from orbit.”

The Jet Propulsion Laboratory is currently working on a concept called the Europa Explorer which would deliver a low orbit spacecraft to determine the presence (or absence) of a liquid water ocean under Europa’s ice surface. It would also map the distribution of compounds of interest for pre-biotic chemistry, and characterize the surface and subsurface for future exploration. “This type of mission,” says McKinnon, “would really allow us to get the hard proof we would all like that the ocean is really there, and determine the thickness of the ice shell and find thin spots if they exist.”

McKinnon added that an orbiter could find “hot spots” that indicate recent geological or even volcanic activity and obtain high-resolution images of the surface. The latter would be needed to plan any successful landing.

Slightly smaller than Earth’s moon, Europa has an exterior that is nearly craterless, meaning a relatively “young” surface. Data from the Galileo spacecraft shows evidence of near-surface melting and movements of large blocks of icy crust, similar to ice bergs or ice rafts on Earth.

While Europa’s midday surface temperatures hover around 130 K (-142 C, -225 degrees F), interior temperatures could be warm enough for liquid water to exist underneath the ice crust. This internal warmth comes from tidal heating caused by the gravitational forces of Jupiter and Jupiter’s other moons which pull Europa’s interior in different directions. Scientists believe similar tidal heating drives the volcanoes on another Jovian moon, Io. Seafloor hydrothermal vents have also been suggested as another possible energy source on Europa. On Earth, undersea volcanoes and hydrothermal vents create environments that sustain colonies of microbes. If similar systems are active on Europa, scientists reason that life might be present there too.

Among scientists there is a big push to get a mission to Europa underway. However this type of mission is competing for funding against NASA’s goal of returning to our own moon with human missions. The proposed Jupiter Icy Moon Orbiter (JIMO) a nuclear powered mission to study three of Jupiter’s moons, fell victim to cuts in science missions in NASA’s Fiscal Year 2007 Budget.

Ross has been designing and improving submarines for over 40 years, but this is the first time he’s designed a craft for use anywhere but on Earth.

“The biggest problem that I see with the robot submarine is being able to drill or melt its way through a maximum of 6 km of the ice, which is covering the surface,” said Ross. “However, the ice may be much thinner in some places. It may be that we will require a nuclear pressurized water reactor on board the robot submarine to give us the necessary power and energy to achieve this”

While Ross proposes using parachutes to bring the submarine to Europa’s surface, McKinnon points out that parachutes would not work in Europa’s almost airless atmosphere.

Ross has received very positive responses to his paper from friends and colleagues, he says, including notable British astronomer Sir Patrick Moore. Ross says his life has revolved around submarines since 1959 and he finds this new concept of a submarine on Europa to be very exciting.

McKinnon classifies the exploration of Europa as “extremely important.”

“Europa is a place is where we are pretty sure we have abundant liquid water, energy sources, and biogenic elements such as carbon, nitrogen, sulfur, phosphorus, etc,” he said. “Is there life, any kind of life, in Europa’s ocean? Questions don’t get much more profound.”

Written by Nancy Atkinson

August 29, 2007December 26, 2015 by Fraser Cain

Podcast: Earth

Another week, another planet. This time we talk about our own home world: Earth. You might think you know the planet beneath your feet, but it’s actually one of the most interesting and dynamic places in the Solar System. Learn about our planet’s formation, weather, its changing climate, and life.

Click here to download the episode

Earth – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

August 27, 2007December 26, 2015 by Fraser Cain

What’s Up this Week: August 27 – September 1, 2007

Monday, August 27 – While it’s going to be very hard to ignore the presence of the Moon tonight, Neptune is a little more than a degree north, and there may be a visible occultation event. Be sure to check IOTA for the most up-to-date information.

Think having all this Moon around is the pits? Then let’s venture to Zeta Sagittarii and have a look at Ascella – “The Armpit of the Centaur.” While you’ll find Zeta easily as the southern star in the handle of the teapot formation, what you won’t find is an easy double. With almost identical magnitudes, Ascella is one of the most difficult of all binaries. Discovered by W. C. Winlock in 1867, the components of this pair orbit each other very quickly – in just a little more than 21 years. While they are about 140 light-years away, this gravitationally bound pair waltz no further apart than our own Sun and Uranus!

Too difficult? Then have a look at Nu Sagittarii – Ain al Rami, or the “Eye of the Archer.” It’s one of the earliest known double stars and was recorded by Ptolemy. While Nu 1 and Nu 2 are actually not physically related to one another, they are an easy split in binoculars. Eastern Nu 2 is a K type spectral giant that is around 270 light-years from our solar system. But take a very close look at the western Nu 1 – while it appears almost as bright, this one is 1850 light-years away! As a bonus, power up in the telescope, because this is one very tight triple star system!

Tuesday, August 28 – In 1789 on this day, Sir William Herschel discovered Saturn’s moon Enceladus. But if Sir William were around tonight, he’d be napping the early evening hours away as the Moon heads quietly for the Earth’s shadow and a total lunar eclipse is about to occur. For those living in the eastern portions of North and South America, the event will begin not long before dawn. The further west you live, the better your chances of observing totality, with the event in progress at moonrise for observers in far eastern Europe, New Zealand and Australia. No matter if you’re staying out late, or getting up early, a total lunar eclipse is well worth watching!

One of the most breathtaking adventures you can undertake is to watch the Moon through a telescope during an eclipse, both at ingress and egress. Craters take on new dimensions and subtle detail as the shadow races across the surface. If you are lucky enough to see totality… Look at the stars around the Moon. What a wonder it is to behold that which is normally hidden by the light!

Try and judge the Danjon scale for yourself. An L4 is an orange moon with a blue shadow at the edge of the dark umbral cone. L3 is brick red with a grey rim. L2 is deep red, with the umbra very dark with a bright outer edge. L1 is a dark eclipse, where the Moon turns almost brown, while a rare L0 means the Moon becomes almost invisible.

Enjoy your eclipse experience and remember to try your hand at photography!

Wednesday, August 29 – Tonight we’ll hop about two fingerwidths north of Nu Sagittarii to have a look at an open cluster that’s a bit more off the beaten path – NGC 6716. Comprised of around 75 genuine cluster members, this 100 million year old cluster will appear almost like a loose globular cluster, with brighter stars superimposed over the field of a mid-sized telescope in a distinctive horseshoe pattern. At magnitude 7.5 it’s not only within range of larger binoculars, but part of challenge lists as well. Be sure not to confuse it with the far more open Collinder 394 about half a degree southwest. Like all Collinder clusters, it’s a large, sparse open one that only contains a handful of stars in a V pattern.

If you’re still feeling adventurous with a larger scope, drop back and take a much closer look at the Nu Sagittarii system. On the southern edge of eastern Nu 2’s influence, you just might catch globular cluster NGC 6717. If not, keep trying because you need a Palomar globular for your studies! At very near magnitude 10, this loose, class VIII globular was discovered by Sir William Herschel on Aug 7th, 1784, and listed as H III.143. Although it will appear as nothing more than a faint, round unresolved area, it truly is a globular cluster. At one time a small cluster of stars was designated as IC 4802 with surrounding nebulosity – but tonight we’ll log it as Palomar 9!

And if you still can’t find Uranus? Try looking about 1.7 degrees south of the Moon after it rises…

Thursday, August 30 – Today celebrates the Yohkoh Mission, launched in 1991. It was a joint effort of both Japan and the United States to monitor solar flares and the corona. While its initial mission was quite successful, on December 14, 2001 the signal was lost during a total eclipse. Unable to reposition the satellite back towards the Sun, the batteries discharged and Yohkoh became inoperable.

Before the Moon rises tonight, let’s have a look at a very curious planetary nebula located around three fingerwidths (RA 17 13 44.21 Dec -37 06 15.9) west of Lambda Scorpii – NGC 6302, better known as the “Bug” nebula.

With a rough visual magnitude of 9.5, the Bug belongs to the telescope – but it’s history as a very extreme planetary nebula belongs to all. At its center is a 10th magnitude star, one of the hottest known. Appearing in the telescope as a small bowtie, or figure-8 shape, huge amounts of dust exist – very special dust. Early studies showed it consisted of hydrocarbons, carbonates and iron. At one time, carbonates were believed associated with liquid water, and NGC 6302 is one of two such regions known is space to contain carbonates – perhaps in a crystalline form.

Ejected at high speed in a bi-polar outflow, further research has shown the presence of calcite and dolomite, causing scientists to rethink where carbonates might be formed. The processes that formed the Bug may have begun 10,000 years ago – meaning it may have by now stopped losing material. Hanging out about 4000 light-years from our own solar system, we’ll never see NGC 6302 as well as the Hubble Telescope presents its beauty, but that won’t stop you from enjoying one of the most fascinating of planetary nebulae!

Friday, August 31 – Tonight we will begin entering the stream of the Andromedid meteor shower, which peaks off and on for the next couple of months. For those of you in the northern hemisphere, look for the lazy “W” of Cassiopeia to the northeast. This is the radiant – or relative point of origin – for this meteor stream. At times, this shower has been known to be spectacular, but let’s stick with an accepted fall rate of around 20 per hour. These are the offspring of Beila’s Comet, one that split apart leaving radically different streams – much like 73/P Schwassman-Wachmann did last year. These meteors have a reputation for red fireballs with spectacular trains, so watch for them in the weeks ahead.

While we’re waiting, let’s head over to the dark side as we take a look at the Barnard 72 Dark Nebula (RA 17 23 02.00 Dec -23 33 48.0), located about a fingerwidth north of Theta Ophiuchi.

While sometimes dark nebulae are hard to visualize because they are simply an absence of stars, patient observers will soon learn to “see in the dark.” The trained eye often realizes the presence of unresolved stars as a type of background “noise” that we simply take for granted – but not E.E. Barnard. He was sharp enough to realize that there were at least 182 places in the sky where these particular areas of nothingness existed, and he correctly assumed they were due to obscuring dark nebulae.

Unlike bright emission and reflection nebulae, these dark clouds are interstellar masses of dust and gas that remain unilluminated. We would probably not even realize they were there except for the fact that they eradicate star fields we know to be present! It is possible that one day they may form stars of their own, but until that time we can enjoy these objects as splendid mysteries – and one of the most fascinating of all is the “Snake.”

Put in a wide field eyepiece and relax… It will come to you. Barnard 72 is only a few light-years in expanse and a relatively short 650 light-years away. If at first you don’t see it, don’t worry. Like many objects, spotting dark nebulae takes some practice.

Sunday, September 1 – On this day 1859, solar physicist Richard Carrington (who originally assigned sunspot rotation numbers) observed the first solar flare ever recorded. Naturally enough, an intense aurora followed the next day. 120 years later in 1979, Pioneer 11 made history as it flew by Saturn. And where is Saturn? Hanging out with the Sun!

As the nights begin to cool and darken earlier for those in the north, it’s time for us to fly with the “Swan” as the graceful arch of the Milky Way turns overhead. Tonight we’ll start by taking a look at a bright star cluster that’s equally great in either binoculars or telescope – M39.

Located about a fist’s width northeast of Deneb (Alpha Cygni), you will easily see a couple of dozen stars in a triangular pattern. M39 is particularly beautiful because it will seem almost three dimensional against its backdrop of fainter stars. Younger than the Coma Berenices cluster, and older than the Pleiades, the estimated age of M39 is at least 230 million years. This loose, bright galactic cluster is around 800 light-years away. Its members are all main sequence stars and the brightest of them are beginning to evolve into giants.

For more of a challenge, try dropping about a degree south-southwest for NGC 7082 – also known as H VII.52. While it is a less rich, less bright and far less studied open cluster, at magnitude 7.5 it is within range of binoculars, and is on many open cluster observing lists. With only a handful of bright stars to its credit, larger telescopes are needed to resolve out many of the fainter members. Be sure to mark your notes for both objects!

August 23, 2007December 26, 2015 by Fraser Cain

Uranus’ Rings Seen Edge On

Once every 42 years, the angle between Uranus and the Earth is perfectly lined up so that the planet’s rings are seen edge on. Since the rings were only discovered back in 1977, this is the first opportunity astronomers will have to view the planet without the glare and dust from the rings. It doesn’t happen on a specific date, though, it’s a little more complicated than that.

Because the Earth goes around the Sun much more quickly than Uranus, there are actually three separate times that Uranus and the Earth line up perfectly: May 3 and August 16 in 2007, and then February 20 in 2008. Unfortunately, during that last point, the Sun will be directly in between our two planets, so we won’t be able to see Uranus.

The first to image Uranus during this special occasion was a team of astronomers from UC Berkeley. They imaged Uranus on May 28th with the near infrared camera and adaptive optics on the W.M. Keck II telescope atop Hawaii’s Mauna Kea. Their images revealed the nearly edge on ring appearing as a bright line passing right through Uranus.

The next images come from Hubble, taken on August 14th. Hubble captured its images on nearly the precise moment when the rings were aligned with the Earth, showing similar features to the Keck image, and also seeing some recently discovered outer rings. The outermost ring, seen by Hubble, is difficult to view in infrared.

Astronomers are hoping these images will reveal more details about the moons that help tend the ring, called Cordelia and Ophelia, keeping it in place. But it’s also thought that there are additional moons in the region, helping to tend all 9 rings. This precise geometry might allow the telescopes to reveal moons that would normally be lost in the glare of the rings.

One other important date:

“December 7 is the Uranian equinox, when the rings are perfectly edge-on to the sun, and after that, there is a brief period again when we will view the dark side of the rings, before they become illuminated again for another 42 years,” said Heidi B. Hammel of the Space Science Institute in Boulder, Colorado.

Original Source: UC Berkeley News Release

August 22, 2007December 26, 2015 by Fraser Cain

Could Enceladus’ Plume Damage Cassini?

Enceladus has a remarkable secret, and scientists want to know more. Something is keeping the moon warm, and creating great plumes of water ice that spew out into the Saturnian system and even contribute to the rings. NASA is sending the Cassini spacecraft back in for another look in 2008; however, some engineers are concerned that the tiny particles might pose a risk to the spacecraft as it flies right through them.

On March 12th, 2008, Cassini is scheduled to pass only 100 km (62 miles) above the surface of Enceladus – a tremendous scientific opportunity. The spacecraft will give scientists an unprecedented look down onto the “tiger stripe” cracks around Enceladus’ southern pole, and the starfish shaped fissures that emanate away. This could be just the observations they need to finally solve the mystery: where’s all this water ice coming from?

But when Cassini passes this close to the planet, it’s going to be flying right through the plumes. Some scientists are worried that ice grains lofted by the jets will impact the spacecraft and damage its sensitive instruments.

Dr. Larry Esposito, one of the researchers working to understand the source of the plumes is presenting some of his research at the European Planetary Science Congress in Potsdam on Thursday 23rd August.

“These plumes were only discovered two years ago and we are just beginning to understand the mechanisms that cause them. A grain of ice or dust less than two millimetres across could cause significant damage to the Cassini spacecraft if it impacted with a sensitive area. We have used measurements taken with Cassini’s UVIS instrument during a flyby of Enceladus in 2005 to try and understand the shape and density of the plumes and the processes that are causing them.”

The size of the particles is key. Using Cassini’s Ultra-Violet Imaging Spectrograph, scientists were able to calculate the amount of water vapour present in the plumes. They were then able to simulate the speed and density of the particles flowing out of the plumes. This let them calculate the average size of the particles at the point where the plumes will be most dense during Cassini’s encounter in 2008.

While the average-sized particle was 1/1000th the size that would cause damage, Esposito is concerned that there could be larger particles lurking in there as well. It would take very high-pressure jets to loft particles this large, and so far, Esposito hasn’t found any. Right now, he’s estimating the chances for a hit to Cassini to be 1 in 500. Better measurements should give a more precise understanding of the risks involved.

How do you like those odds?

August 22, 2007December 26, 2015 by Fraser Cain

Google Earth… for Astronomy

All right, this is the coolest thing ever. You know Google Earth, that cool software application that lets you explore satellite photography of the whole planet. Well, some clever Google engineers have flipped the software inside out, letting you explore the Universe with a similar interface.

This new addition to Google Earth is called “Sky in Google Earth”. It allows you to zoom around the heavens, with various Hubble Space Telescope images highlighted. You can click on the special objects, like the Orion Nebula, and then see the Hubble photograph of the region.

The images of the entire sky are made up from the Digitized Sky Survey and the Sloan Digital Sky Survey. The Digitized Sky Survey covers almost the entire sky, contains about a million objects. The Sloan Digital Sky Survey only has about 25% of the sky covered, but in much more detail, comprising hundreds of millions of images.

For all the images captured by Hubble, you can see bigger versions of the images, and then link out to press releases and additional resources on the web.

I’ve got to say, I’m really impressed with the way this project has started out. I can envision a future where more and more sky surveys are put into the program, and maybe even different observatories, so you can see what the sky looks like in X-rays, infrared, etc.

I think this will also help highlight how little of the sky has actually been captured in any detail. Perhaps this will spur on the development of additional robotic sky surveys to continue capturing the Universe in greater and greater detail. Still, it’s an amazing start – nice work Google.

To get a copy of Google Earth, go to http://earth.google.com/. The latest version of the software, 4.2, contains the additional sky watching features.

Original Source: Hubble News Release

August 22, 2007December 26, 2015 by Mark Mortimer

Book Review: The Galactic Supermassive Black Hole

Combining large scale astronomical observations with the careful reasoning of physics leads to the widely encompassing field of astrophysics. Apparently, the physical laws that rule interactions on Earth also rule the actions across our universe. Fulvio Melia takes this consideration to task in his book The Galactic Supermassive Black Hole. Within the book, the equations bring reason to some very murky observations and sharpen our view of the heavens.

The target of Melia’s book is our own active galactic centre; the region in and about Sagittarius A*. One of today’s postulations is that each galaxy has a supermassive black hole at its centre. Thus, we’d expect to see a black hole in or near Sagittarius A*. But this raises the question, “How does one see a black hole?”. For, of course, a black hole absorbs everything about it, including light, so there is little for satellites to detect. Nevertheless, though we aren’t able to directly see a black hole, there are many other indicators foretelling such an astronomical entity. Thus, by observation, inference and a great deal of reliance upon physical laws, Melia dishes out reason about the contents of our galactic centre.

To make reason, Melia provides the tools and background throughout his book. He begins with a brief review of relevant observational data about Sagittarius A*. In particular, he looks at emission strengths and characteristics for various energy levels. As an example of the difficulties of this subject, much of the observation supports each other, but yet there’s no exact match. Thus, there’s the need to account for the common problems with astronomy, in that targets move, viewing platforms shake and differences arise for no known cause. Nevertheless, with diagrams, graphs and satellite survey results, Melia shows the data that’s important and provides ways and means to interpret it.

After this review, Melia takes the reader through some simple and some esoteric mathematical manipulations. The simple is setting up transformation matrices for four-dimensional space time. He then goes on to utilize these constructs as a substrate for simulations of the magnetohydrodynamic properties at the galactic centre. These equations come after some development, though many are results from other, external works or papers (that are usually referenced). The equations aren’t present for an intimidation factor, however. Rather, Melia uses them to construct comparative figures and graphs. And, with these, he brings together the hard relations of physics with the softer visages from the satellites. In consequence, the reader, if they can follow the mathematical development, will have effective and viable tools for analyzing the expected properties at our, and other, active galactic nuclei. This is as wonderfully complete as a reader could expect for introductory analytical tools.

And the target audience of this book is the people who are thinking of extending their interests into active galactic nuclei. Melia’s stated goal with the book is to help young astronomers come up to speed with mature primary literature on Sagittarius A*. This book is a great resource for doing just this. By providing background references, establishing equations and comparing theory to observation, this book has excellent breadth. With the derivation of equations and presentation of typical hard data, this book has good depth. For those well into the wonders of astronomy and astrophysics, reading this book would be just the treat to help them reach further into this specialized area of astrophysics.

However, for those readers who are more interested in results or enjoying the view, this book may have too much depth. Integrals, distribution functions and relativistic motion are all present and are necessary preparations for many of Melia’s discussions. His expectation, apparently, is that the reader is comfortable with this technical level. Thus, he doesn’t draw out derivations. A reader, unfamiliar with this level, may soon find themselves grasping for understanding.

Yet, for those who want to make a serious commitment in the field of active galactic nuclei, particularly of Sagittarius A*, this is a very thorough and polished book. The chapters and material follow on naturally. There aren’t surprises nor need for guess work. Somewhat unsettling is the ending. Here, Melia skips from a paragraph on needed telescope upgrades to the next paragraph, where he states that his book is at best a work in progress. The reader, therefore, is left hanging. There’s very little on expected future research efforts, centres of research or practitioners in the field. Thus, if a person is contemplating further study, they may know more of what to do from reading this book, but they will need to look elsewhere on how best to contribute to the field.

The light from far away stars, beautiful in its own right, can carry great meaning. As it bounces off of dust or reflects about great masses of matter, we can infer details. Fulvio Melia in his book The Galactic Supermassive Black Hole combines the little information we can detect from our galactic centre together with our accepted laws of physics. This foundation is just waiting for the next contributor to extend our knowledge into the further reaches of space.

Read more reviews or purchase a copy online from Amazon.com

August 22, 2007December 26, 2015 by Fraser Cain

SMART-1 Links Geologic and Volcanic Activity on the Moon

ESA’s SMART-1 spacecraft was purposely crashed into the Moon on September 3, 2006. But before it died, it analyzed the Moon in incredible detail. One of the key questions it’s attempting to help scientists answer: how were surface features formed? By putting together data from both SMART-1 and NASA’s Clementine spacecraft, scientists have detailed views of some of the fine details that will help answer these questions.

Most of the Moon’s surface features – all those big craters – were created approximately 350-750 million years after the formation of the Moon, during a period called the Lunar Late Heavy Bombardment period. Almost all of the large lunar basins 300 km or larger were created during that period. And then after that, many of these basins were filled in by lava from volcanic activity.

By combining images from SMART-1 and Clementine, scientists can now see many of the fine geological structures, using SMART-1’s AMIE micro-camera. During its orbits, SMART-1 passed very close to the surface of the Moon, and took low-elevation images that revealed very fine scale geological features that had been undetected before now.

One example of this is the Humorum basin; a nice, round compact basin that was created by a simple impact event. The spacecraft data shows a thin crust and mass concentration within a small area.

This is different from the Procellarum basin. This region is a large, extended, complex basin that is moderately thick and has no mass concentration. It might have been formed by faulting associated with an adjacent crater, and not a gigantic impact.

Each lunar crater has a story to tell. The SMART-1 data is helping scientists understand when the Moon was volcanically active, and how and when the lava flowed into ancient impact craters.

Original Source: EPC News Release

August 21, 2007December 26, 2015 by Fraser Cain

Details on Germany’s Lunar Exploration Orbiter

The Moon is going to be a busy place. NASA is sending the Lunar Reconnaissance Orbiter in 2008, and will be sending humans back as early as 2020. Germany, a member of the European Space Agency, announced they’ll be getting in the lunar game too. Their recently announced Lunar Exploration Orbiter will be heading to the Moon in 2012, giving our satellite another satellite of its own.

The new details on the Lunar Exploration Orbiter were announced at the European Planetary Science Congress, which is being held this week in Potsdam.

The mission will consist of two spacecraft flying in formation, and taking simultaneous measurements of the lunar surface. As with NASA’s Stereo mission, targeted at the Sun, this twin vision will give scientists a true stereoscopic view of the Moon’s surface features. The Moon, in thrilling 3-D!

It will also be able to study the Moon’s magnetic and gravitational fields in 3 dimensions as well, both on the near side, and the far side of the Moon. The main satellite will weigh about 500 kg (1100 pounds), and the secondary satellite will only weigh about 150 kg (330 pounds), carrying duplicate magnetic and gravity instruments.

The main satellite carries a microwave radar that will allow it to peer beneath the lunar surface to a depth of several hundred metres. At maximum depths, it’ll be able to resolve structures two metres across, and within the top few metres, it’ll be able to resolve structures just a few millimetres across. This will help scientists track the distribution of rocks and particles, and help reveal the history of impacts.

LEO will create high resolution maps of the entire lunar surface in stereo and multispectral bands. The whole mission should last 4 years, so it will even be able to watch for new impacts, by looking for new craters and detecting impact events. That should be pretty impressive.

August 21, 2007December 26, 2015 by Fraser Cain

STS-118: Endeavour Touches Down Safely in Florida

After 13 days in space, the space shuttle Endeavour touched down safely in Florida today. NASA managers actually decided to bring the shuttle home a day early, to beat Hurricane Dean, currently ravaging the East Coast of Mexico. Despite the nearby stormy weather, conditions at Cape Canaveral were perfect for landing.

NASA managers gave the Endeavour crew instructions to begin their de-orbit burn at 11:05 am EDT. 30 minutes later they fired their retro rockets for 3.5 minutes, slowing their orbital speed enough to get caught by the Earth’s atmosphere. The shuttle descended through breezy, blue skies across Costa Rica, Cuba, and then onto the 3-mile (4.8 km) landing strip in Florida. It rolled to a stop at 12:32 pm EDT.

The reason for the early return was Hurricane Dean, which had recently passed through Jamaica, and is now tearing up the coastal resorts in Mexico. The category 5 hurricane ended up turning south, but had it continued north, it could have forced an evacuation of the Kennedy Space Center in Florida.

Engineers were a little concerned about the landing, because of the small chunk taken out of the shuttle’s protective heat tiles on its underside. A small piece of foam fell off the shuttle’s insulated external fuel tank and gouged out a hole across two tiles. NASA analyzed the damage and calculated that it wouldn’t pose a risk to the shuttle or the crew. They were certain that it wouldn’t even damage the shuttle’s aluminum frame, requiring extensive repairs. They landed safely, but what kind of damage the shuttle took still remains to be seen.

During their time in space, the crew of STS-118 installed a new truss element onto the station, transfered cargo, and reorganized some communications equipment.

Original Source: NASA News Release