Posted on by Ian O'Neill

NASA Official Wants a Six Month Stay on Moon

Lunar footprint from the Apollo missions (NASA)

NASA is exploring the possible designs for lunar bases, intended for an extended stay on the Moon. A NASA official from the Advanced Capabilities Division also said on Friday that they may be inspired by a concept based on the technology of the International Space Station (ISS). Very little official indication about the future of NASA’s lunar policy has come to light, so this is interesting news. Although the statement was suitably sketchy, a six-month extended mission to the Moon seems to be most likely. How does this development compare with the lunar settlement designs already proposed?

When Carl Walz, director of NASA’s Advanced Capabilities Division, says “I would anticipate that we would build something similar as what we are building for the ISS, but maybe something different,” I think we can conclude that his department is keeping its options open as far as the future of Moon bases is concerned. But it seems settlement design isn’t very far along either…

Moon base rover concept - could be used for long-term missions (NASA)

Putting uncertainties in lunar base designs to one side, Waltz did confirm that he envisions a long-term, six-month stay over on the Moon, “We need to establish a long, extended presence on the moon, up to six months — same as the time we spend at ISS,” the veteran astronaut told AFP during a forum on the future of NASA at the University of Miami, Florida. The ISS remains mankind’s best experiment into long-term living in space, so its little wonder the station should be used as a model for Moon bases.

The ISS is due for completion in 2010 and houses three scientists for several months at a time. Also, there is enough room for the regular Shuttle crews who arrive to deliver experiments and attach modules. It’s not hard to imagine a future manned lunar base can be used in a similar way, perhaps have a small long-period contingent of scientists, allowing space for short-term visits.

The Apollo 15 lunar rover, awaiting the return of man to the Moon (NASA)

NASA hopes to return to the Moon by 2020 to build a permanent outpost on our planet’s natural satellite. The settlement will need transportation, communication and power systems (see Building a Base on the Moon: Part 4 – Infrastructure and Transportation), allowing lunar astronauts to have the freedom to carry out scientific research on the lunar surface. Many lunar base concepts utilize local materials to fabricate many aspects of a permanent lunar habitat, and continued research by satellites such as the Japanese probe SELENE will aid future colonists prospect for useful minerals and ores.

“We will live at the moon, work at the moon, do sites at the moon and use its resources.” – Walz

It looks as if NASA is working toward a modular settlement design, using the technology that powers the ISS and would be in keeping with “erectable”, or modular designs. Initially, building Moon bases on Earth (or low Earth orbit) and sending them to the lunar surface appears to be the most viable solution. Once a human presence can be established on the Moon, it seems possible that Mars habitats could be fabricated there and sent to the Red Planet. Exciting times.

More about building a manned base on the Moon:

Source: Physorg.com

Posted on by Fraser Cain

Why are there Black Holes in the Middle of Galaxies?

Question: Why are Black Holes in the Middle of Galaxies?

Answer: The black holes you’re thinking of are known as supermassive black holes. Stellar mass black holes are created when a star at least 5 times larger than the Suns out of fuel and collapses in on itself forming a black hole. The supermassive black holes, on the other hand, can contain hundreds of millions of times the mass of a star like our Sun.

Astronomers are now fairly certain that these supermassive black holes are at the heart of almost every galaxy in the Universe. Furthermore, the mass of these black holes is somehow tied to the mass of the rest of the galaxy. They grown in tandem with each other.

When large quantities of material falls into the black hole, it chokes up, unable to get consumed all at once. This “accretion disk” begins to heat up and blaze brightly in many different wavelengths, including X-rays. When supermassive black holes are actively feeding, astronomers call these quasars.

So how do these black holes get there in the first place? Astronomers aren’t sure, but it could be that the dark matter halo that surrounds every galaxy serves to focus and concentrate material as the galaxy was first forming. Some of this material became the supermassive black hole, while the rest became the stars of the galaxy. It’s also possible that the black hole formed first, and collected the rest of the galaxy around it.

Astronomers just don’t know.

Posted on by Fraser Cain

Why Haven’t Planets Been Detected Around Alpha Centauri?

Toliman
Artist impression of Alpha Centauri

Question: Why aren’t astronomers looking for planets around nearby stars like Alpha Centauri?
Answer: That’s a great question. Since Alpha Centauri is only a little over 4 light-years away, why aren’t astronomers studying it for planets, instead of the more distant stars.

Astronomers have included stars like Alpha Centauri in their search for extrasolar planets, they just haven’t found them yet. That’s because the techniques used to find extra solar planets require very large planets orbiting very close to their parent stars.

The first technique is called the radial velocity method. This is where the gravity of the planet yanks its parent star back and forth. The changes in the star’s velocity are measurable in the light that reaches the Earth.

The second technique looks for transits. This is where the planet passes in front of the parent star, dimming it slightly. By measuring the amount the light dims, astronomers are able to know if there’s a planet there, calculate its size and even determine what’s in its atmosphere.

A third technique detects microlensing events. A closer star focuses the light from a more distant star with its gravity. From Earth, we see a flare in brightness as the two stars line up perfectly. If the closer star has a planet orbiting it, that will change the light curve that astronomers detect, allowing them to calculate the size of the planet.

Most of the planets discovered to date are known as Hot Jupiters. These are planets much larger than Jupiter that orbit within the orbit of Mercury.

A team of astronomers led by Javiera Guedes from the University of California think that an Earth-sized planet should be detectable orbiting Alpha Centauri. They’re working to get a single dedicated telescope to watch the star, and work out if there are planets there. According to their calculations, it should only take about 5 years of intense observations by a dedicated telescope to work out the answer.

Posted on by Fraser Cain

Stuart Blasts Star Naming Companies

When I pitched a story idea to Tammy Plotner about how a president of a public observatory deals with those companies that offer to name stars, I was expecting (hoping) for something pretty negative. I think my request was something like, “could you debunk this please”? The article she actually wrote, Name a Star – Real or Ripoff, was much more nuanced, honest and forthright than I was expecting – I’m really glad she took the direction she did, and reminds me why I’m glad Tammy’s writing for Universe Today.

It’s an interesting dilemma. These people are selling something they have no right to sell and have to be dishonest about it. The best companies provide the coordinates to a real star, and the worst…

Anyway, Stuart over at Cumbrian Sky wrote the opinion I was expecting from Tammy. Completely hard line, but a very well defended position. It’s a great read – Star Naming, Fun or Foul.

If any other blogs out there want to chime in on this topic, I’ll be happy to update this page and link to your opinions as well.

Posted on by Tammy Plotner

What’s Up – The Weekend SkyWatcher’s Forecast

It’s big. It’s bright. It’s the Moon! Even though the dark skies will be trashed thanks to the influence of this weekend’s Moon, there’s still a lot of astronomy we can practice together. Grab your telescopes or binoculars and let’s head out, because… Here’s what’s up!

Friday, April 18 – Tonight, if you’re looking at the Moon near the southern cusp you’ll spy two outstanding features. The easiest is crater Schickard – a class V mountain-walled plain spanning 227 kilometers. Named for German astronomer Wilhelm Schickard, this beautiful old crater with subtle interior details has another crater caught on its northern wall which is named Lehmann. But, look further south for one of the Moon’s most incredible features – Wargentin. Among the many strange things on the lunar surface, Wargentin is unique. Once upon a time, it was a very normal crater and had been so for hundreds of millions of years, then it happened: either a fissure opened in its interior, or the meteoric impact which formed it caused molten lava to begin to rise. Oddly enough, Wargentin’s walls did not have large enough breaks to allow the lava to escape, and it continued to fill the crater to the rim. Often referred to as “the Cheese,” enjoy Wargentin tonight for its unusual appearance…and be sure to note Nasmyth and Phocylides as well.

Saturday, April 19 – Despite the Moon’s overpowering light, you may have noticed brilliant blue-white Spica very near the Moon tonight. Take the time to look at this glorious helium star, which shines 2300 times brighter than the Sun which lights tonight’s Moon. Roughly 275 light-years away, Alpha Virginis is a spectroscopic binary. The secondary star is about half the size of the primary and orbits it about every four days from its position of about 18 million kilometers from center to center… That’s less than one-third the distance at which Mercury orbits the Sun (here are some planet Mercury facts). The two stars can actually graze during an eclipse. Oddly enough, Spica is also a pulsating variable and the very closeness of this pair make for fine viewing – even without a telescope!

While we’re out, have a look at R Hydrae about a fingerwidth east of Gamma – which is itself a little more than fistwidth south of Spica. R Hydrae (RA 13 29 42 Dec -23 16 52) is a beautiful, red, long-term variable first observed by Hevelius in 1662. Located about 325 light-years from us, it’s approaching – but not so very fast. Be sure to look for a visual companion star as well.

Sunday, April 20 – Tonight’s Full Moon is often referred to as the “Pink Moon” of April. As strange as the name may sound, it actually comes from the herb moss pink or wild ground phlox. April is the time of blossoming and the “pink” is one of the earliest widespread flowers of the spring season. As always, it is known by other names as well, such as the Full Sprouting Grass Moon, the Egg Moon, and the coastal tribes referred to it as the Full Fish Moon. Why? Because spring was the season the fish swam upstream to spawn.

While skies are bright, let’s take this opportunity to have a look at Alpha Canis Minoris, now heading west. If you’re unsure of which bright star is, you’ll find it in the center of the diamond shape grouping in the southwest area of the early evening sky in the northern hemisphere. Known to the ancients as Procyon, “The Little Dog Star,” it’s the eighth brightest star in the night sky and the fifth nearest to our solar system. For over 100 years astronomers have known this brilliant star was not alone – it had a companion, and a very unusual one. 15,000 times fainter than the parent star, Procyon B is an example of a white dwarf whose diameter is only about twice that of Earth. But its density exceeds two tons per cubic inch! (Or, a third of a metric ton per cubic centimeter.) While only very large telescopes can resolve this second closest of the white dwarf stars, even the moonlight can’t dim its beauty.

Posted on by Fraser Cain

A Portal to Another Universe?

In episode 56 of Astronomy Cast, I noted that hoping that a black hole will lead to another dimension is sort of like a frog thinking that a blender will take him to another realm.

Astronomy Cast listener Isaac Windham animated the sequence, just to really drive the point home…

And here’s the transcript from the show, so you’ll all get the reference. Thanks Isaac!

Fraser: Why do people think we might live in a black hole? That seems kind of crazy to me.

Pamela: It’s a lot of science fiction. There’s this idea in science fiction that you can fly into a black hole and emerge in a completely different part of our universe, in an alternate universe… and so from these fiction writings, the idea has gotten into the zeitgeist that you fly into a black hole and you fly into a different universe – which means a universe can be inside of a black hole.

The problem is real black holes just lead to death.

Fraser: I guess that’s the question – it’s like a frog asking if I hop into that blender, will it lead me to another universe?

Pamela: Exactly

Fraser: No, no it won’t – a universe of pain.

Pamela: It will lead to death, and yeah – where death leads to is a personal question not based in facts and not addressable in this show.

Fraser: Right, so it’s almost like it’s become a kind of philosophical question and it goes back to that extra-dimensional conversation we had in a well-received episode we did back in the day. I guess it’s kind of like it’s different – could it be so different that it’s not really a devastating matter crusher? Could it be a bold new universe we could explore? (Says the frog hopping into his blender.

Posted on by Fraser Cain

Carnival of Space #50

This week the Carnival of Space moves to another new home, the blog for KentuckySat (KySat). We’ve got some interesting stories this week: news on the Rocket Racing League, images of Phobos, and a plan to send monkeys to Mars. That’s right… monkeys.

Click here to read the Carnival of Space #50

And if you’re interested in looking back, here’s an archive to all the past carnivals of space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, let me know if you can be a host, and I’ll schedule you into the calendar.

Finally, if you run a space-related blog, please post a link to the Carnival of Space. Help us get the word out.

Posted on by Nancy Atkinson

Stellar Birth in the Galactic Wilderness

This just in from the pretty pictures department at NASA. NASA’s Galaxy Evolution Explorer (GALEX) shows young stars sprouting up in a relatively desolate region of space more than 100,000 light-years from the galaxy’s bustling center. This striking image is a composite of ultraviolet data from GALEX and radio data from the Very Large Array in New Mexico, and shows the Southern Pinwheel galaxy, also known simply as M83. “It is absolutely stunning that we find such an enormous number of young stars up to 140,000 light-years away from the center of M83,” said Frank Bigiel, lead investigator of the new Galaxy Evolution Explorer observations. For comparison, the diameter of M83 is only 40,000 light-years across.

M83 is located 15 million light-years away in the southern constellation Hydra. The ultraviolet image was taken by NASA’s Galaxy Evolution Explorer between March 15 and May 20, 2007.

In this view, the main spiral, or stellar, disk of M83 looks like a pink and blue pinwheel, while its outer arms appear to flap away from the galaxy like giant red streamers. It is within these so-called extended galaxy arms that, to the surprise of astronomers, new stars are forming.

This side-by-side comparison shows the Southern Pinwheel galaxy, or M83, as seen in ultraviolet light (right) and at both ultraviolet and radio wavelengths (left). While the radio data highlight the galaxy’s long, octopus-like arms stretching far beyond its main spiral disk (red), the ultraviolet data reveal clusters of baby stars (blue) within the extended arms.

Astronomers speculate that the young stars seen far out in M83 could have formed under conditions resembling those of the early universe, a time when space was not yet enriched with dust and heavier elements.

“Even with today’s most powerful telescopes, it is extremely difficult to study the first generation of star formation. These new observations provide a unique opportunity to study how early generation stars might have formed,” said co-investigator Mark Seibert of the Observatories of the Carnegie Institution of Washington in Pasadena.

Original News Source: NASA GALEX press release

Posted on by Nancy Atkinson

Mars Express: Looking Beneath Mars’ Surface

MARSIS
MARSIS fully deployed orbiting Mars. Image credit: ESA

To truly know and understand another world, planetary scientists need to look beneath the surface of that planet. This has been done on a small scale by looking inside impact craters, a la Opportunity and Spirit on Mars. But that only provides information for one area on a big planet. To get the global picture of the subsurface, a radar sounder instrument was developed for ESA’s Mars Express spacecraft. The Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) experiment has now been successfully used for the first time to look beneath Mars’ south polar ice cap, opening up the third dimension for planetary exploration. “We have demonstrated that the polar caps at Mars are mostly water ice, and produced an inventory so now we know exactly how much water there is,” says Roberto Orosei, MARSIS Deputy Principal Investigator.

The data from MARSIS’ probe of the ice cap is still being analyzed, but scientists say they expect some surprising results to be revealed.

MARSIS is built to map the distribution of liquid and solid water in the upper portions of the Martian crust, and can investigate Mars’ subsurface up to a depth of 5 km. If reservoirs of water are detected, it will help us understand the hydrological, geological, climatic and possibly biological evolution of Mars. “At the south pole of Mars, we are seeing through ice 3.7 km thick. A small calculation shows that we could see through ice down to 20 km or more thick at Mars,” says Ali Safaeinili, MARSIS co-investigator.

No one had ever used a radar sounder from orbit on another planet before. So the team was uncertain it would work as planned. The subsurface of the planet might have been too opaque to the radar waves or the upper levels of Mars’ atmosphere (ionosphere) might have distorted the signal too much to be useful.

But, the instrument worked perfectly.

Every time a radar wave crosses a boundary between different substances, it generates an echo that the orbiter detects.

See ESA’s 3-D simulation of the radar instrument.

While MARSIS is still collecting data, a follow-up instrument is already operating at Mars. The Shallow Subsurface Radar (SHARAD) on NASA’s Mars Reconnaissance Orbiter works at higher frequencies than MARSIS and can see more details in the signals it receives from the underground layers, but it can’t penetrate the surface quite as far.

The technique’s success is prompting scientists to think of all the other places in the Solar System where they would like to use radar sounders. One obvious target is Jupiter’s icy moon, Europa. There, a radar sounder could probe the moon’s icy crust to help understand the puzzling features we see on the surface. It may even see the interface at the bottom of the ice where an ocean is expected to begin.

Asteroids and comets could be thoroughly scanned by a radar sounder, producing three-dimensional maps of their interior– perhaps exactly the data we will need if, one day, we have to nudge one out of Earth’s way. Also, this type of radar instrument could be used on our own planet to look inside Earth’s polar caps and ice sheets to determine their stability.

Mars Express has been orbiting the Red Planet since December 2003. It carries seven scientific experiments, including MARSIS, which was built by the Italian Space Agency with cooperation from JPL and the University of Iowa.

Original News Source: ESA press release

Posted on by Nancy Atkinson

Inflation Theory Takes a Little Kick in the Pants

Inflation theory proposes that the universe underwent a period of exponential expansion right after the Big Bang. One of the key predictions of inflation theory is the presence of a particular spectrum of “gravitational radiation”—ripples in the fabric of space-time that are really hard to detect but thought to exist. But a team of researchers has now found that gravitational radiation can be produced by a mechanism other than inflation. So this type of radiation, if eventually detected, won’t provide the conclusive evidence for inflation theory that was once was thought to be a certainty.

“If we see a primordial gravitational wave background, we can no longer say for sure it is due to inflation,” said noted astronomer Lawrence Krauss, from Case Western Reserve University.

Inflation theory first was proposed by cosmologist Alan Guth in 1981 as a means to explain some features of the universe that had previously baffled astronomers, such as why the universe is so close to being flat and why it is so uniform. Today, inflation remains the best way to theoretically understand many aspects of the early Big Bang universe, but most of the theory’s predictions are somewhat vague enough that even if the predictions were observed, they probably wouldn’t provide a clear-cut confirmation of the theory.

But gravitational radiation was considered one of the key predictions of inflation theory, and detection of this spectrum was regarded among physicists as “smoking gun” evidence that inflation did in fact occur, billions of years ago.

Gravitational radiation is a prediction of Einstein’s Theory of General Relativity. According to the theory, whenever large amounts of mass or energy are shifting around, it disrupts the surrounding space-time and ripples emanate from the region where the shift occurs. These ripples aren’t easily detected, but there is one experiment designed to look directly for this radiation, the Laser Interferometer Gravitational Wave Observatory (LIGO) in Livingston, Louisiana. The upcoming Planck Mission, set to launch in 2009 will look for it indirectly by looking at the cosmic microwave background.

Until now it was widely believed that detecting gravitational radiation in the form of polarized light from the CMB would confirm inflation theory, since it was thought inflation would be the only way this radiation could be produced. But Krauss and his team have raised the issue of whether this radiation can be unmistakably tied to inflation.

Krauss’s team proposes that a phenomenon called “symmetry breaking,” can also produce gravitational radiation. Symmetry breaking is a central part of fundamental particle physics, where a system goes from being symmetrical to a low energy state that is not symmetrical. Krauss’s explanation is that a “scalar field” (similar to an electric or magnetic field) becomes aligned as the universe expands. But as the universe expands, each region over which the field is aligned comes into contact with other regions where the field has a different alignment. When that happens the field relaxes into a state where it is aligned over the entire region and in the process of relaxing it emits gravitational radiation.

This is all fairly confusing, but the sweetened condensed version is that if gravitational radiation is ever detected, that event won’t necessarily verify inflation theory. Therefore, whether inflation theory can ever be confirmed remains to be seen.

Krauss’s paper “Nearly Scale Invariant Spectrum of Gravitational Radiation from Global Phase Transitions” is published in the Aprill 2008 Physical Review Letters.

Original News Source: Case Western Reserve University press release