The Sloan Telescope used to conduct BOSS
A long time ago in a galaxy far far away…Well, to be precise, 14 billion years ago and at the beginning of the universe was the Big Bang. Ever since that moment, our universe has been expanding, but over the last 7 billion years that expansion has been accelerating. Why? Scientists don’t really know, so they came up with an ominous term as a placeholder: Dark Energy (Another possible explanation is that that our theory of gravity is wrong, but we’ll skip that for now). Recent calculations project dark energy makes up nearly 70% of the mass-energy of the universe. 70% of the universe is a mystery? That’s the kind of puzzle that inspires scientists to craft unique experiments.

One of those is BOSS, the Baryon Oscillation Spectroscopic Survey, is a new project to create a 3-D map of over 2 million galaxies and quasars representing the best data ever obtained on the large-scale structure of the universe. Baryon oscillations began as pressure waves through the hot plasma of the early universe. Those waves left an imprint on the matter that makes up the universe, including the dark matter. The survey will essentially act as a ruler, in order to measure how the universe has been expanding.

Next Monday, you’ll be able to meet David Schlegel, the principal investigator of BOSS. He’ll be part of a panel of Lawrence Berkeley Laboratory scientists discussing their search for dark energy. As a primer, check out QUEST’s story on Dark Energy from last year. The piece features astrophysicist Saul Perlmutter, who will also be speaking at the event.

See QUEST's Video on Dark Energy below:

QUEST on KQED Public Media.


Dark Secrets: What Science Tells Us About the Hidden Universe

Where: Berkeley Repertory Theater, 2025 Addison Street, Berkeley

When: Monday, October 26th 7-830 PM

Cost: FREE

Details: No mystery is bigger than dark energy — the elusive force that makes up three-quarters of the Universe and is causing it to expand at an accelerating rate. KTVU Channel 2 health and science editor John Fowler will moderate a panel of Lawrence Berkeley National Laboratory scientists who use phenomena such as exploding stars and gravitational lenses to explore the dark cosmos.

The Hubble Space Telescope being serviced by Space Shuttle
Atlantis astronauts in May 2009. Credit: NASAFour hundred years ago, Galileo built his telescope and became the first on record to point the new device (invented the previous year) at objects in the sky. Today (in fact, even as I write!) what has become a symbol for the current state of evolution of the telescope—the Hubble Space Telescope–is being repaired and upgraded by the crew of the Space Shuttle Atlantis…for the last time.

Galileo's telescope had a magnification of only about 27x, allowing him to see that Venus has phases like the Moon, Jupiter has four large moons of its own, Saturn does not appear as a simple disk but has unusual "projections" to either side, and the Milky Way contains far more stars than is apparent to the naked eye. And though these are features that can be seen through the least powerful home telescopes today, Galileo's observations changed the way we look at the universe.

Hubble has done the same thing, but on a modern scale of magnitude. Not a large telescope by the standards of ground-based behemoths like Keck in Hawaii (Hubble's primary mirror is 2.4 meters in diameter), Hubble's "edge" is it's location in space, orbiting the Earth over 300 miles high, outside of our atmosphere. Particularly in its earlier days before ground based telescopes were using adaptive optics techniques to compensate for atmospheric distortion, Hubble's vision on the universe was unparalleled in its clarity.

Here's is a recap of a few of the many big discoveries Hubble has made possible:

Dark Energy: By accurately measuring the distance and velocity of distant supernovae, over a large range of distances, Hubble has refined out knowledge of the rate of expansion of the universe–leading to the discovery that the expansion of the universe is actually accelerating, contrary to what was expected. Scientists suggest the existence of a mysterious "dark energy" throughout the universe that exerts an antigravitational repulsive pressure on the cosmos.

Age of the Universe: Since Edwin Hubble (for whom the Space Telescope was named) discovered that the universe is expanding, astronomers have been trying to determine how long ago the expansion began–how long ago the "starting gun" of the Big Bang was fired, and thus the beginning of the universe. Through precise observations with the Hubble, astronomers in recent years have been able to peg it between 12 and 14 billion years. (Most recently, observations made with the WMAP mission have honed that down to 13.7 billion years, give or take 0.13 billion.)

Supermassive Blackholes: Hubble found the clues that point to the existence of "supermassive" blackholes at the heart of maybe most–or every–galaxy. The Milky Way's own central blackhole has a mass equivalent to four million Suns.

Stellar Dust Disks: Before the first extrasolar planets were actually detected, Hubble observations revealed that flat disks of dust encircling young and developing star systems–aka "protoplanetary disks"–is commonplace. This has given us a glimpse at what our own solar system may have looked like before the planets formed.

It has been seven years since the last Hubble servicing mission, with another servicing scheduled a few years ago cancelled in the wake of the Columbia disaster. Several failing systems will be repaired or replaced this time, and other instruments are receiving upgrades that will make Hubble more powerful than ever in its declining years.

This mission to service the Hubble will be the last. Since NASA is retiring the Space Shuttle fleet after 2010, we will no longer have a space vehicle large enough to carry upgrade and replacement equipment to and from the Hubble. After that, the next new big space-based descendent of Galileo's spyglass will be the James Webb. Stay tuned…

Yuri Alexyevich Gagarin, "Columbus of the Cosmos" Last Thursday evening, over 3500 people came to the California Academy of Sciences to help celebrate Yuri. This gathering was not the only celebration of its kind. Two-hundred and eight parties in forty-six countries on eight continents celebrated Yuri's Night between April 6 and 12th of this year.  So who is Yuri and why does he deserve such accolades?

Yuri Alexyevich Gagarin was a Soviet cosmonaut.  He was the first human in space and is often referred to as "the Columbus of the Cosmos".   His spacecraft Vostok-1 orbited the Earth on April 12, 1961 for the duration of 108 minutes.   Yuri's Night, usually celebrated on April 12^th celebrates this historic first flight.

Yuri's Night also celebrates another April 12^th anniversary notable in the annals of space travel.  Twenty years after Yuri Gagarin's historic flight, the first NASA space shuttle flight, STS-1 was launched into space.  STS is short for Space Transportation System.  NASA names each flight STS with the chronological number after it.  STS-1 was launched on April 12, 1981; the shuttle orbited the earth 37 times during a 54.5 hour mission.

Since 1961, our interest in space and the exploration of its depths has magnified.  Recently NASA launched the Kepler mission.  On March 7^th, 2009, the Kepler Mission successfully launched from Cape Canaveral, Florida.  Kepler, which is a specialized telescope, was designed to find the first Earth-size planets orbiting stars within a "habitable zone". A habitable zone is an orbit around a star that would enable a planet to formulate and upkeep an atmosphere and the ability for water to form in pools on the planet's surface.  Liquid water is believed to be essential for the formation of life.  Thus from the nascent flight of orbiting our own Earth, space travels has evolved to look amongst other start.  This progress is certainly something worthy of celebration!

An exhibit on the Kepler Mission along with other NASA initiatives like SOFIA, LCROSS and NLSI fascinated guests last Thursday night.  For one guest, meeting Buzz Aldrin in person was the highlight of his night.   My favorite aspect of the evening was a 3-D rendered tour of the moon and neighboring space.  I am anxious to see what will be the new annal of space exploration when April 12^th and Yuri's Night comes around again in 2010.

A scale model of the LCROSS payload.

Update: This Friday morning, October 9th at 4:30AM PDT, the upper stage of the Centaur rocket carrying LCROSS will smash into a crater near the moon's south pole. The LCROSS spacecraft will follow close behind, making measurements and taking images of the emerging lunar debris before it too meets its dramatic end. Soon thereafter, we may learn if water can in fact be mined from the dark, cold lunar depths. For you moon junkies, NASA Ames Research Center in Moffett Field is also hosting an "LCROSS Impact Night"this Thursday, beginning at 7PM.

With a price tag of 80 million dollars and a little more than two years in the making, the LCROSS spacecraft will begin its voyage atop an Atlas V rocket. Shortly thereafter it will shepherd the upper stage of the rocket in an orbit around the moon to position it in place for a colossal impact that will kick up a cloud of lunar dust forty miles high. The goal is to see if water exists on the moon and if it does, buried deep beneath the lunar soil, accumulating over millions of years of impacts with comets, it would accelerate our efforts to establish a permanent lunar base. Think of it as a rest stop to refuel (oxygen is an essential ingredient of rocket fuel) before arriving at the next closest planetary body, Mars, a journey which takes roughly 600 days, or 200 times longer than a trip currently to the Moon from Earth.

The avid QUEST viewer may recall that we covered the LCROSS mission in the first episode of QUEST back in 2007. A lot has happened since then, including most notably a change in the launch date which at the time of this post was scheduled for May 20th, 2009. Peter Schultz's vertical gun range has been outfitted with some dizzyingly high-tech cameras, which are capable of recording at tens of thousands of frames per second (one can record at one million frames per second) to capture the most minute progressions of the lunar impact simulations performed with the thirty-foot tall vertical gun. The suite of nine instruments aboard LCROSS, known as its "payload", has been mercilessly subjected to thermal, vibration and acoustic testing to make sure they can withstand the effects of launch and the harsh celestial environment. And then there's the spacecraft itself which we weren't able to show you in 2007 because the spacecraft still had to be transformed from a set of designs into a compact, robust structure the size of a small car by a team of sharp, young Northrop Grumman engineers. Moreover, amateur astronomers, armed with telescopes ten inches or more, are now being encouraged by NASA to share their images of LCROSS' historic lunar impact.

One of the most impressive attributes of the LCROSS mission is its rapid turnaround and cost containment which in turn highlight the innovative production model that was essential in making LCROSS a reality. Imagine the spirit of Silicon Valley, with its entrepreneurial zeal and efficiency, fusing with some of the sharpest minds in astrophysics and aeronautical engineering, and you have a glimpse of the unique nature of this small but nimble mission which just may forever change our understanding of the moon and its secrets.

Watch the LCROSS Rocket to the Moon" television story online.

For several years there has been a lot of buzz about the detection of extra-solar planets, or exoplanets: planets orbiting stars other than our Sun. However, due to the limits in technology and observational capabilities, to date only large, gas giant planets orbiting close to the stars (so called "Hot Jupiters") have been found, with a possible exception or two.

The main method for detecting exoplanets is by spectroscopically observing a tiny "wobble" in a star caused by the gravitational tug of a massive planet in orbit. Only Jupiter-sized planets have enough pull to produce a wobble in their star that we can detect—and the closer they are to their star, the shorter their orbital period and the more wobbles we can measure in a given period of time. The gravity of an Earth-sized planet is too feeble for this and planets at Earth-like distance orbit only once in many months.

But NASA is about to launch a new spacecraft, Kepler, whose mission is to detect Earth-sized planets at Earth-like distances from their stars. Kepler will launch on March 5th, and will eventually move into an orbit around the Sun. In essence, Kepler is a giant space camera designed to "stare" at a chosen patch of the sky continuously for years to come.

So what exactly is Kepler looking for in its unblinking stare contest with the stars in its vision? Kepler won’t be looking for microwobbles in those stars. Kepler will detect planets through the transit method. A transit is when a planet crosses in front of its star, blocking off a tiny amount of the star's light for a time.

A number of the hot Jupiters have been detected by their transits across their stars: a large planet can block a measurable amount of their star's light. But the drop in a star's brightness caused by an Earth-sized planet is far smaller—and if that planet only orbits its star every year or so, with its infrequent transit lasting only a few hours, an observer would have to stare long and hard to notice it.

Kepler will be based in space, and will be able to observe its target patch of sky continuously, uninterrupted by the cycles of day and night on Earth. Also by virtue of being in space, Kepler won't be hampered by Earth's turbulent and obscuring atmosphere—so there will be far less "noise" in the starlight, noise that can hide a minute drop in brightness. Finally, Kepler's sensitive digital camera system is an array of 42 CCD chips positioned at the focus of a 0.95 meter telescope, which will image an area of the sky about 12 degrees in diameter—equivalent to the area of sky you can cover with your open hand at arm's length.

Kepler will stare at a patch of sky near the constellation Cygnus, constantly monitoring about 150,000 stars for the next few years, looking for minute drops in brightness that may be the passage of Earth-sized planets.

Kepler won't reveal the composition or atmospheres of Earth-sized planets, or any telltale signs of life. Perhaps more importantly at this stage of our exploration of space, Kepler should give us an idea of how numerous Earth-sized planets are out there—whether or not they are as commonplace as depicted on Star Trek…

Good luck, Kepler, and stare on!

The Vernal Equinox, where the Sun crosses the Celestial
Equator (red line) on the first day of Spring (March 20/21).
Credit: Space.com/Starry Night

"Can you tell me about the upcoming beginning of the Age of Aquarius?" said the voice on the phone. "I heard that it starts this Saturday…"

Now, I get a lot of phone calls and emails from people with astronomy and sky related questions. Very often it's something like, "What was that thing that tried to land in my front yard yesterday evening?!" or, "Is it true that Mars will be closer to the Earth this weekend than it has been in a gazillion years?" I've even had one or two asking if it's true that the world is ending in 2012.

Okay, I'm embellishing a bit. Those are all very good questions, and I do my best to provide a science-based answer — like, "Venus tried to land in your yard," or "The Mars extra-close encounter happened in 2003… and it had only been less than a century since the previous time," or, "We'll just have to wait for 2012 to roll around to find out…"

As for the Age of Aquarius question, that got me to wondering. I've always regarded this issue as astrology-related more than astronomy, but I also realized there are physical underpinnings to the definition. So I fired up Google and clarified some of the details for myself. The first thing I learned is that, among astrologers at least, there is little agreement on precisely when the Age of Aquarius is supposed to begin (or if it's already begun). Different astrologers at different times and from different parts of the world have tried to define this, resulting in multiple schools of thought on the subject.

But from a purely astronomical standpoint, the delineation of these Ages is based on a natural physical cycle, just as a year is defined by Earth's motion around the Sun and a day is defined by Earth's rotation on its axis.

An astrological Age (aka "Great Year") is determined by the position of the Vernal Equinox — at least by one of the schools of thought… The Vernal Equinox is that point in the sky occupied by the Sun when it crosses the Celestial Equator heading into the Northern Hemisphere. So, you can think of the Vernal Equinox as a distinct point on the sky (and it's easy to locate on the first day of Spring: Just look at the Sun — I take that back: DON'T look at the Sun!)

But the position of the Vernal Equinox shifts over time due to a cycle of change in the orientation of the Earth's rotation. The Earth spins like a top, but also like a top it undergoes a gyrating motion, called precession. One complete gyration takes about 26,000 years — so all of the points in the sky defined by Earth's spinning (the celestial poles and equator, and, yes, the Vernal Equinox) move around the sky over 26,000 years.

At this moment, the Vernal Equinox is in the constellation Pisces — at least, within the region of the sky defined by modern astronomers as encompassing all the stars of Pisces. So, if one were to acknowledge the constellation boundaries according to modern astronomers, then one would say that we are in the Age of Pisces still (and, by the same definition of constellation boundaries, the Vernal Equinox will remain in Pisces until about the year 2600, when it will cross the border into Aquarius.)

However, there is little agreement among different groups of astrologers on where one constellation ends and another begins–and to my knowledge none of them have adopted the modern astronomical boundaries.

So, when does the Age of Aquarius begin? Depends on who you talk to….

Mark your calendars for March 16 through 28. Don't ask why, yet. Now, read on….

Composite image showing centers of urban light emission
Credit: NASAWant a chance to do some "citizen" science, contribute to an international investigation, and have some fun to boot? An opportunity is coming up in March: Globe At Night. All you need is your eyes….

The problem is summed up in two words: light pollution. A good deal of light produced by human civilization–streetlights, porch lights, shopping malls, security lighting, night time work lights, store fronts, parking lot lights, billboards, neon signs, the list is lengthy–shines or reflects upward into the atmosphere, there scattering off of suspended particles, like dust grains, water droplets, ice crystals and the like.

The scattered light shines back down from the sky, and we see it as a dull nocturnal glow, sometime faint, and sometimes quite pronounced. The amount of scattering particles in the air has an effect on the brightness of the night sky, but the root of the matter is the amount of light sources whose light escapes upward. The closer you are to the heart of an urban area, the more light pollution you will be subjected to.

So what? What's so harmful about that sky glow? Sometimes it can even look kind of pretty….

Well, the fact is, if you've never seen a clear night sky far from sources of major light pollution, you may not appreciate what you're missing: the sight of a clear and dark night sky in which you can literally see thousands of stars. And if you have seen a pristinely dark night sky before, think about the fact that, in 2008, half the population of the Earth was living in cities, many of whom may never have been out of their urban worlds, and for whom the night sky is naturally a dull version of day with a handful of washed out stars above.

There are also effects of light pollution on wildlife that include disturbance of day/night sleep cycles, less cover of darkness from predators, and even effects on plant life.

Globe At Night is a program that's been going on for a few years now whose aim is to measure and monitor the varying levels of light pollution around the world by using individual people as the instruments of measurement.

And it's pretty simple to participate in. The idea is that the brighter the light pollution is in any given location, the few stars you can see. The faintest stars quickly become drowned out in the sky glow, leaving only the brighter ones for your eyes to pick out. All you have to do is go outside on one or more nights in the last half of March, find the constellation Orion (which is pretty easy to find, even in a city), and count the number of stars you see there. Then, report your count through the Globe At Night website, where you'll also be able to see the observations of everyone else around the world, as well as find full instructions for participating.

Now, calendars marked? Know where Orion is? Have a sweater handy? You're all set….

The Mars Science Laboratory. Credit: NASA/JPL-Caltech

When I hear about the search for alien life, it's hard not to think about all the science fiction movies with little green men and Earth-destroying spacecraft. But it's an idea that's far from science fiction for scientists at NASA Ames.

NASA is preparing to send their next rover to the surface of Mars, known as the Mars Science Laboratory. It follows the legacy of the twin rovers Spirit and Opportunity, who have survived far longer than NASA scientists expected. After four years, they're still sending data from the Martian surface. (For an update, check out this post from QUEST blogger Ben Burress).

The Mars Science Lab rover will have a few upgrades, though. It's much larger than Spirit and Opportunity and will be nuclear-powered — meaning no solar cells that are vulnerable to dust storms. It will also be carrying the most advanced lab equipment yet, some of which will look for organic matter on the surface. The goal to discover how habitable the surface could have been for life.

When it comes to what kind of life, it's microbial life that many scientists believe is the best case scenario. There have been a number of recent discoveries that are promising evidence that liquid water once existed on the surface. But if even the conditions were right for life then, they're certainly not right today. Thanks to a thin atmosphere, Mars is bombarded by solar radiation and conditions are dry and cold. Still, many scientists think there's a possibility that life could survive in the subsurface, where it's warmer and more sheltered.

The question most of us would ask, though, is: even if we found extraterrestrial life someday, how would we recognize it? NASA scientist Chris McKay explained his take to me. It turns out there are some basic things scientists believe they could look for. You can hear what he has to say in this audio clip:

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McKay brought up another interesting point — we've already sent earthlings to Mars. The NASA rovers were built in clean rooms, but they're not completely sterile. Chances are there are microbes from Earth on Mars now, protected inside machinery we built. McKay believes this contamination is reversible, and there's already a policy in place to protect both Earth and Mars known as planetary protection.  You can hear McKay explain why it's so important in this clip.

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No matter what the outcome of the Mars Science Lab mission, there's a lot more to discover about what Mars is like today and about its past.

Watch the Looking for Mars Life on Planet Earth report online.

The Hoba meteorite in Namibia, Africa, the largest known
meteorite found; approximately the size of 2008 TC3 before
it burned up in our atmosphere.News Flash! Asteroid 2008 TC3, on a collision trajectory with Earth, made a meteoric atmospheric entry into the skies above Sudan, Central Africa Tuesday morning, October 7^th (local time-about 7:46 PM PDT). Entering the atmosphere at a speed of 12.8 kilometers per second, it exploded with the force of a low-level nuclear bomb…

Wait a moment… an asteroid you say? Hitting the Earth? Isn't that supposed to spell some kind of disaster, such as Dino-slaughter? Isn't that something we send people like Bruce Willis and Clint Eastwood to deal with before it becomes a problem down here on Earth?

Okay, so Asteroid 2008 TC3 wasn't an Earth-killer, but rather a crowd-thriller. It wasn't miles across-not even tens of meters across. It was, perhaps, a few meters in size, similar in volume to mid-size car. In fact, it didn't even hit the Earth's surface, but vaporized in the atmosphere.

Sounds a bit anticlimactic-and that's not the half of it. It's not even a rare event! Objects of this size are believed (and sometimes observed) to enter Earth's atmosphere a few times each year. So what's the blog deal?

The blog deal is this: this is the first time that an object this size has been detected approaching the Earth a significant period of time before actually impacting-in this case, about a day. 2008 TC3 was detected by the Mount Lemmon telescope in Arizona on Monday. The detection was reported to the Minor Planet Center, which collects such observations from observatories large and small (including Chabot Space & Science Center) in order to track and predict possible Earth impactors. In turn, the MPC alerted NASA of the impending impact.

Observers on the ground reported the fireball lit up the skies with the intensity of the Full Moon. A nearby airliner (not in danger, as the fireball exploded tens of kilometers above the ground, well above the airliner's flight path) reported seeing a bright flash.

In a sense, this event was kind of a dress rehearsal for the international system of predicting, and possibly defending against, impacts on Earth by much larger asteroids and comets. We already know of thousands of Near Earth Objects (NEOs-asteroids and comets that cross Earth's orbit and are large enough to cause a catastrophe should they strike the Earth). It is also expected that there are many thousands more that we haven't yet detected, being small enough to "fly under the radar" of our NEO detecting network.

Early detection and sustained tracking of NEOs is key to the protection plan against impact disaster. If we can accurately predict an impact far enough in advance, we could potentially send a spacecraft to it and gently "nudge" it off course and deflect the eventual impact.

So ends the existence of another chunk of rock that had, up to that point, been serenely orbiting the Sun for billions of years…

Artist concept of lightning on Venus. Credit: NASAVenus has reentered our sky in its part-time job as the Evening Star, appearing as a uniquely brilliant white beacon over the western horizon after sunset.

With all the attention that the exploration of certain other planets has received lately, I feel that Venus exploration has fallen off our radar a bit, and that it is high time for an update.

There is no lack of exploration of Venus today: NASA's MESSENGER spacecraft, bound for Mercury, flew by Venus twice (2006, 2007), making observations on the fly; Japan is currently planning to send a climate orbiter mission ("Planet C") there in 2010; and the European BepiColombo will perform a couple of Venus flybys of its own, in 2013, on its way to Mercury.

Most notably, the European Venus Express orbiter is in the middle of a two-year mission of exploration, and has revealed new and fascinating things about Venus–a planet whose cloud-shrouded surface kept us mostly ignorant about it until recent decades. (Before the 1960's it was even speculated that Venus might be a steamy swamp or rain forest world!)

Here's a quick recap of some of the highlights of Venus Express's findings:

"Hurricanes" at the poles: Venus Express's VIRTIS instrument, which is able to probe several different layers of the atmosphere, has put together a detailed picture of wind behavior at different latitudes and different altitudes. What was discovered from these observations is that Venus has giant, hurricane-like vortexes capping its poles. Winds within these systems all flow in generally the same direction, as you'd expect with hurricanes, circling mostly windless "eyes" at their centers at the poles.

Lighting: Evidence of lightning on Venus was detected by earlier orbiter and lander missions, and Venus Express has confirmed it–maybe more lightning activity than on Earth. What makes Venus's lightning unique among the planets with lightning (Earth, Jupiter, and Saturn, as far as we know) is that it's the only case where lightning is formed by something other than clouds of water droplets–in Venus's case, sulfuric acid droplets do the trick. Lightning can be an important factor in that it breaks up atmospheric molecules and allows them to recombine in different forms.

Active volcano search: It has long been suggested that there may be active volcanoes on Venus today, though no direct evidence (like images of erupting volcanoes, for example) have yet been obtained. Venus Express has measured large variations over time in the concentrations of sulfur dioxide in Venus's atmosphere–a compound that on Earth comes from volcanic eruptions.

There's a lot more to say about Venus, as it is a world as varied and fascinating as the Earth (minus the life forms, as far as we know). Though it may not be the hottest vacation spot in the solar system, with its pressure cooker of a toxic, acid-laced atmosphere, it is one of those great mysteries that we actually get to watch unfold before us as exploration of it moves forward.