Posted on by Irene Antonenko

Thin Skinned and Wrinkled, Mercury is Full of Surprises

[/caption]

Until relatively recently, Mercury was one of the most poorly understood planets in the inner solar system. The MESSENGER mission to Mercury, is changing all of the that. New results from the Mercury Laser Altimeter (MLA) and gravity measurements are showing us that the planet closest to our sun is thin skinned and wrinkled, which is very different from what we originally thought.

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft was launched back in 2004. It took a long time getting to its destination, completing 3 flybys of Mercury before finally entering orbit a little over a year ago. Currently, the spacecraft is in a highly eccentric polar orbit, approaching the planet much closer in the north than in the south. This allows the northern hemisphere to be probed and imaged at enviably high resolutions, but leaves the southern hemisphere poorly understood.

Even so, the data returned from MESSENGER is showing us some quite unanticipated findings. Two papers from the MESSENGER team, published in today’s issue of Science, are showing some surprising results from the laser altimeter and gravity experiments.

Using NASA’s Deep Space Network, Earth-based radio tracking of MESSENGER has allowed minute changes in the spacecraft’s orbit to be monitored and recorded. From this, Dr. Maria Zuber of MIT and her team calculated a model of Mercury’s gravity. Meanwhile, the on-board laser altimeter has provided invaluable topographic information. Combined together, these data have allowed the MESSENGER team to glean a great deal of information about the planet’s interior workings.

One of the most striking findings is that the iron-rich core of Mercury is very large. A combination of measurements and models suggest that the core has both a solid interior portion and a liquid outer portion. And while it is not certain how much of the core is solid and how much is liquid, it is clear that the total core has a radius of about 2030 km. This is a huge core, representing 83% of Mercury’s 2440 km radius!

Interior of Mercury vs Earth
The internal structure of Mercury is very different from that of the Earth. The core is a much larger part of the whole planet in Mercury and it also has a solid iron-sulfur cover. As a result, the mantle and crust on Mercury are much thinner than on the Earth.
Credit: Case Western Reserve University

Furthermore, these calculations suggest that the layer above the core is much denser than previously expected. Results from MESSENGER’s X-Ray spectrometer indicate that the crust, and by extension the mantle, are too low in iron to explain this high density. Dr. Zuber’s team think that the only way to explain this discrepancy is by the presence of a solid iron-sulfur layer just above the core. Such a layer could be anywhere from 20 to 200 km thick, leaving only a very thin crust and mantle at the top. This kind of interior structure is completely different from what was originally suggested for Mercury, and it is nothing like what we have seen in the other planets!

This striking fact may help explain some unexpected altimeter results, which show that Mercury’s topography has less variation than other planets. The total difference between the highest and lowest elevations on Mercury is only 9.85 km. Meanwhile, the Moon has a total difference of 19.9 km between its highest and lowest points, and on Mars this difference is 30 km. Dr. Zuber and her team speculate that the presence of the core so close to the surface could keep the mantle hot, allowing topographic features to relax. In such a scenario, the lithosphere under tall impact-formed mountains would sink down into a mushy mantle that cannot support their weight. Conversely, the thin lithosphere under impact basins would rebound upwards, taking part of the mobile mantle with it.

In fact, the gravity data shows evidence of exactly this kind of process, in the form of “mascons”. These mass concentrations form when large imacts make the local crust very thin, allowing denser mantle material to rise closer to the surface as the lithosphere rebounds from the impact event. Mascons are well known from studies on the Moon and Mars, and now MESSENGER’s gravity data has revealed three such mascons on Mercury, located in the Caloris, Sobkou, and Budh basins.

Mercury Topography Northern Hemisphere
The elliptical polar orbit of the MESSENGER spacecraft means that measurements at the North Pole of Mercury are much better than those at the South Pole, or even at the equator. This is evident in the better spatial resolution that can be seen at the high latitudes in this elevation map of the northern hemisphere. Major impact structures are identified by black circles.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Interestingly enough, the mascons in Sobkou and Budh basins are not immediately obvious. They only show up when the effects of a regional topographic high are adjusted for. This topographic feature is a large quasi-linear rise that extends over half the circumference of Mercury in the mid-latitudes. The rise even passes through the northern part Caloris basin (which is large enough that its mascon is not overwhelmed by the rise). Studies of this rise by the MESSENGER team suggest that it is relatively young, having formed well after the formation of the basins, after the volcanic flooding of their interiors and exteriors, and even after some of the later impact craters that cover the flooded surfaces.

Dr. Zuber and her team also identified another young topographically elevated region, the Northern Rise, located in the lowlands surrounding the North Pole. They speculate that these young rises represent a buckling of the lithosphere, which happened when the planet’s interior cooled and contracted. This interpretation is supported by the presence of lobate scarps and ridges that can be seen around the planet, and which represent faulting of the crust when it was compressed.

So, it seems that Mercury is unlike the other planets of the Solar System. It appears to have a disproportionately large core that is covered by a thin skin of mantle and lithosphere. Furthermore, this skin seems to have wrinkled like a raisin’s when the huge core of the planet shrunk as it cooled.

Sources
Gravity Field and Internal Structure of Mercury from MESSENGER, Smith et al., Science V336 (6078), 214-217, April 13 2012, DOI:10.1126/science.1218809

Topography of the Northern Hemisphere of Mercury from MESSENGER Laser Altimetry, Zuber et al., Science V336 (6078), 217-220, April 13 2012, DOI:10.1126/science.1218805

Posted on by Jason Major

Keck Observatory Fires Up MOSFIRE

The MOSFIRE instrument's "first light" image of The Antennae galaxies, acquired on April 4 2012.

[/caption]

Last week, on April 4, 2012, the W.M. Keck Observatory’s brand-new MOSFIRE instrument opened its infrared-sensing eyes to the Universe for the first time, capturing the image above of a pair of interacting galaxies known as The Antennae. Once fully commissioned and scientific observations begin, MOSFIRE will greatly enhance the imaging abilities of “the world’s most productive ground-based observatory.”

Installed into the Keck I observatory, MOSFIRE — which stands for Multi-Object Spectrometer For Infra-Red Exploration — is able to gather light in infrared wavelengths. This realm of electromagnetic radiation lies just beyond red on the visible spectrum (the “rainbow” of light that our eyes are sensitive to) and is created by anything that emits heat. By “seeing” in infrared, MOSFIRE can peer through clouds of otherwise opaque dust and gas to observe what lies beyond — such as the enormous black hole that resides at the center of our galaxy.

MOSFIRE can also resolve some of the most distant objects in the Universe, in effect looking back in time toward the period “only” a half-billion years after the Big Bang. Because light from that far back has been so strongly shifted into the infrared due to the accelerated expansion of the Universe (a process called redshift) only instruments like MOSFIRE can detect it.

The instrument itself must be kept at a chilly -243ºF (-153ºC) in order to not contaminate observations with its own heat.

(Watch the installation of the MOSFIRE instrument here.)

Astronomers also plan to use MOSFIRE to search for brown dwarfs — relatively cool objects that never really gained enough mass to ignite fusion in their cores. Difficult to image even in infrared, it’s suspected that our own galaxy is teeming with them.

The impressive new instrument has the ability to survey up to 46 objects at once and then do a quick-change to new targets in just minutes, as opposed to the one to two days it can typically take other telescopes!

Unprocessed image of M82 taken with MOSFIRE on April 5, 2012. (W. M. Keck Observatory)

Images taken on the nights of April 4 and 5 are just the beginning of what promises to be a new heat-seeking era for the Mauna Kea-based observatory!

“The MOSFIRE project team members at Keck Observatory, Caltech, UCLA, and UC Santa Cruz are to be congratulated, as are the observatory operations staff who worked hard to get MOSFIRE integrated into the Keck I telescope and infrastructure,” says Bob Goodrich, Keck Observatory Observing Support Manager. “A lot of people have put in long hours getting ready for this momentous First Light.”

The two Keck 10-meter domes atop Mauna Kea. (Rick Peterson/WMKO)

Read more on the Keck press release here.

The W. M. Keck Observatory operates two 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Big Island of Hawaii.  The spectrometer was made possible through funding provided by the National Science Foundation and astronomy benefactors Gordon and Betty Moore.

Posted on by Jason Major

Polar Telescope Casts New Light On Dark Energy And Neutrino Mass

The 10-meter South Pole Telescope in Antarctica at the Amundsen-Scott Station. (Daniel Luong-Van, National Science Foundation)

[/caption]

Located at the southermost point on Earth, the 280-ton, 10-meter-wide South Pole Telescope has helped astronomers unravel the nature of dark energy and zero in on the actual mass of neutrinos — elusive subatomic particles that pervade the Universe and, until very recently, were thought to be entirely without measureable mass.

The NSF-funded South Pole Telescope (SPT) is specifically designed to study the secrets of dark energy, the force that purportedly drives the incessant (and apparently still accelerating) expansion of the Universe. Its millimeter-wave observation abilities allow scientists to study the Cosmic Microwave Background (CMB) which pervades the night sky with the 14-billion-year-old echo of the Big Bang.

Overlaid upon the imprint of the CMB are the silhouettes of distant galaxy clusters — some of the most massive structures to form within the Universe. By locating these clusters and mapping their movements with the SPT, researchers can see how dark energy — and neutrinos — interact with them.

“Neutrinos are amongst the most abundant particles in the universe,” said Bradford Benson, an experimental cosmologist at the University of Chicago’s Kavli Institute for Cosmological Physics. “About one trillion neutrinos pass through us each second, though you would hardly notice them because they rarely interact with ‘normal’ matter.”

If neutrinos were particularly massive, they would have an effect on the large-scale galaxy clusters observed with the SPT. If they had no mass, there would be no effect.

The SPT collaboration team’s results, however, fall somewhere in between.

Even though only 100 of the 500 clusters identified so far have been surveyed, the team has been able to place a reasonably reliable preliminary upper limit on the mass of neutrinos — again, particles that had once been assumed to have no mass.

Previous tests have also assigned a lower limit to the mass of neutrinos, thus narrowing the anticipated mass of the subatomic particles to between 0.05 – 0.28 eV (electron volts). Once the SPT survey is completed, the team expects to have an even more confident result of the particles’ masses.

“With the full SPT data set we will be able to place extremely tight constraints on dark energy and possibly determine the mass of the neutrinos,” said Benson.

“We should be very close to the level of accuracy needed to detect the neutrino masses,” he noted later in an email to Universe Today.

The South Pole Telescope's unique position allows it to watch the night sky for months on end. (NSF)

Such precise measurements would not have been possible without the South Pole Telescope, which has the ability due to its unique location to observe a dark sky for very long periods of time. Antarctica also offers SPT a stable atmosphere, as well as very low levels of water vapor that might otherwise absorb faint millimeter-wavelength signals.

“The South Pole Telescope has proven to be a crown jewel of astrophysical research carried out by NSF in the Antarctic,” said Vladimir Papitashvili, Antarctic Astrophysics and Geospace Sciences program director at NSF’s Office of Polar Programs. “It has produced about two dozen peer-reviewed science publications since the telescope received its ‘first light’ on Feb. 17, 2007. SPT is a very focused, well-managed and amazing project.”

The team’s findings were presented by Bradford Benson at the American Physical Society meeting in Atlanta on April 1.

Read more on the NSF press release here.

Posted on by Jason Major

Star Lab Needs Payloads!

The multi-section Star Lab suborbital vehicle. (Credit: 4Frontiers Corp.)

[/caption]

Star Lab, the next-generation vehicle for suborbital experiments developed by the Florida-based 4Frontiers Corporation, is well on its way toward its first successful flight — and it’s looking for payloads.

First reported on Universe Today by Jason Rhian in November of last year, Star Lab consists of stacked and subdivided cylindrical sections customized to hold scientific experiments. Contained within a rocket vehicle affixed to the wing of a Starfighters, Inc. F-104 supersonic aircraft, Star Lab will be launched during flight to attain an altitude of about 100 km, going suborbital and achieving 3 1/2 minutes of microgravity before descending.

“If Star Lab proves itself viable this could open the door to a great many scientific institutions conducting their research by using the Star Lab vehicle,” Mark Homnick, CEO of 4Frontiers Corporation, told Universe Today in November.

(Read Science On The Wings of Starfighters by Jason Rhian)

A high-purity environment within the Star Lab compartments will ensure no contamination from the outside can interfere with payloads contained within, making Star Lab suitable for both non-organic and bio-med experiments.

A scale prototype of a Star Lab payload section, molded in ABS plastic. (4Frontiers/J. Major)

Alternatively, the payload compartments can be made accessible to the external environment, allowing for atmospheric sampling.

After descent, Star Lab will splash down into the Atlantic and be retrieved by ship. Clients can expect to have their payloads returned within a 24-hour period — a quick turnaround especially essential for biological experiments.

In addition, Star Lab payloads can be accessed up to 24 hours before launch, allowing for any last-minute adjustments, minor installations or fine tuning.

Currently Star Lab is moving into its flight test phase of development, when the F-104s will go through a series of incremental tests up to and including an actual launch of the vehicle. This will determine how well it handles the stresses of flight and how to best — and most safely — perform the actual launch, slated for September 2012.

A maneuver only ever executed in military operations, Star Lab will become the first commercial vehicle to be launched from an aircraft.

(Read StarFighters, Inc. – The Supersonic Research Fleet Expands by Tammy Plotner)

Star Lab has 14 contracts signed for payloads at this time, and is right now working on a partnership with the payload-specialist company Kentucky Space to co-develop a successful market for bio-med experiments.

“We are looking for payloads… we’re real, we’re viable, and we have the best deal that I know of in respect to costs and what we provide,” Homnick said during an interview on March 15, 2012. “We’ll have the lowest cost and the highest launch rate, anywhere.”

At this point, signups with Star Lab require only a signature… no payment is required until the vehicle is proven.

“There’s even a contingency in there… we have to show with our prototypes that we are launching in the summer that they actually perform,” Homnick added. “One, they have to reach the altitude — over 80 kilometers — and two, we have to return the payloads for our prototype. And then, after all that, they would actually pay us… half up front, and half after launch.”

And if that’s not a good enough deal, the state of Florida is helping pick up some of the bill.

Under NASA’s Florida Space Grant, commercial ventures taking place in Florida are subject to a rebate program. Once a payload is launched, Space Lab customers can receive a refund from Space Florida of 1/3 of their cost.

Starting at $4,000 (after the Space Florida rebate), including integration and return costs, getting an experiment suborbital has never been so cost-effective.

“The whole concept is to make it really inexpensive and convenient to fly a lot of payloads,” Homnick said. “With ten launches a year, and up to thirteen payloads per launch, there’s a high launch rate.”

And with such convenience, Star Lab will help get the future of space research off the ground — literally.

Members of the Star Lab team during a fast taxi test at Kennedy Space Center's Shuttle Landing Facility. (4Frontiers Corp.)

“We’re real, we’re viable, and we have the best deal that I know of… we’ll have the lowest cost and the highest launch rate, anywhere.”

– Mark Homnick, CEO of 4Frontiers Corporation

4Frontiers will be at the Space Flight Payloads Workshop on Friday, March 23 at the Florida Solar Energy Center from 10 am to 5 pm. See more about Star Lab and what’s coming next from 4Frontiers here.

4Frontiers Corporation, the principal developer of Star Lab, was founded in 2005 in Florida, USA. 4Frontiers is an emerging space commerce company focused on developing fundamental space-related capabilities and resources essential for a long-term human presence in space. 4Frontiers will address the potential of the four most promising space frontiers: Earth orbit, the Moon, Mars and asteroids.

Posted on by Jason Major

Playing With Water… in Space!

Expedition 30 astronaut and chemical engineer Don Pettit continues his ongoing “Science off the Sphere” series with this latest installment, in which he demonstrates some of the peculiar behaviors of thin sheets of water in microgravity. Check it out — you might be surprised how water behaves when freed from the bounds of gravity (and put under the command of a cosmic chemist!)

See more Science off the Sphere episodes here.

Posted on by Nancy Atkinson

Solid Buckyballs in Space are Stacked Like ‘Oranges in a Crate’

NASA's Spitzer Space Telescope has detected the solid form of buckyballs in space for the first time. To form a solid particle, the buckyballs must stack together like oranges in a crate, as shown in this illustration. Image credit: NASA/JPL-Caltech

[/caption]

From a JPL press release:

Astronomers using data from NASA’s Spitzer Space Telescope have, for the first time, discovered buckyballs in a solid form in space. Prior to this discovery, the microscopic carbon spheres had been found only in gas form in the cosmos. The new work, led by Prof. Nye Evans of Keele University, appears in a paper in the journal Monthly Notices of the Royal Astronomical Society.

Formally named buckminsterfullerene, buckyballs are named after their resemblance to the late architect Buckminster Fuller’s geodesic domes. They are made up of 60 carbon molecules arranged into a hollow sphere like a football. Their unusual structure makes them ideal candidates for electrical and chemical applications on Earth, including superconducting materials, medicines, water purification and armour.

In the latest discovery, scientists using Spitzer detected tiny specks of matter, or particles, consisting of stacked buckyballs. They found the particles around a pair of stars called “XX Ophiuchi,” 6,500 light-years from Earth, and detected enough to fill the equivalent in volume to 10,000 Mount Everests.

“These buckyballs are stacked together to form a solid, like oranges in a crate,” said Prof. Evans. “The particles we detected are miniscule, far smaller than the width of a hair, but each one would contain stacks of millions of buckyballs.”

Buckyballs were detected definitively in space for the first time by Spitzer in 2010. Spitzer later identified the molecules in a host of different cosmic environments. It even found them in staggering quantities, the equivalent in mass to 15 Earth moons, in a nearby galaxy called the Small Magellanic Cloud.

In all of those cases, the molecules were in the form of gas. The recent discovery of buckyballs particles means that large quantities of these molecules must be present in some stellar environments in order to link up and form solid particles. The research team was able to identify the solid form of buckyballs in the Spitzer data because they emit light in a unique way that differs from the gaseous form.

“This exciting result suggests that buckyballs are even more widespread in space than the earlier Spitzer results showed,” said Mike Werner, project scientist for Spitzer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “They may be an important form of carbon, an essential building block for life, throughout the cosmos.”

Buckyballs have been found on Earth in various forms. They form as a gas from burning candles and exist as solids in certain types of rock, such as the mineral shungite found in Russia, and fulgurite, a glassy rock from Colorado that forms when lightning strikes the ground. In a test tube, the solids take on the form of dark, brown “goo.”

“The window Spitzer provides into the infrared universe has revealed beautiful structure on a cosmic scale,” said Bill Danchi, Spitzer program scientist at NASA Headquarters in Washington. “In yet another surprise discovery from the mission, we’re lucky enough to see elegant structure at one of the smallest scales, teaching us about the internal architecture of existence.”

Read the team’s paper here.

More info at the Royal Astronomical Society

Posted on by Nancy Atkinson

Dancing Water Drops In Earth Orbit

An astronaut once told me that fellow space flier Don Pettit could fix anything with a paper clip. Indeed, Pettit has nicknames like Mr. Wizard and Mr. Fixit, and he is well-known for his Saturday Morning Science videos during his first stay on the International Space Station and his “Zero G Coffee Cup” from a space shuttle mission he was on in 2008. Now in his second long-duration stint on the ISS, Pettit has a new video series called “Science off the Sphere” and the first video is above. Pettit uses “knittin” needles (watch the video to hear Pettit’s pronunciation) and water droplets to demonstrate physics in space, and shows what fun astronauts can have with water in zero-G with his ‘dancing’ water droplets.

This new video series is partnership between NASA and the American Physical Society. But there’s more than just videos, as at the end of each video Pettit poses a challenge question. Submit your answers at the Science Off the Sphere website for a chance to have your name read from space and receive a snazzy t-shirt from Earth.

Here’s this week’s Challenge Question:
Continue reading “Dancing Water Drops In Earth Orbit”

Posted on by Nancy Atkinson

Former Astronaut John Grunsfeld to Lead NASA Science Directorate

John Grunsfeld. Credit: NASA

[/caption]

As was rumored earlier, NASA has named physicist and former astronaut John Grunsfeld as their new associate administrator for the Science Mission Directorate.

“It is an honor and a privilege to be offered the opportunity to lead NASA’s Science Mission Directorate during this exciting time in the agency’s history,” Grunsfeld said. “Science at NASA is all about exploring the endless frontier of the Earth and space. I look forward to working with the NASA team to help enable new discoveries in our quest to understand our home planet and unravel the mysteries of the universe.”

Grunsfeld is taking over for Ed Weiler, who retired from NASA on Sept. 30, and Grunsfeld will officially start his new job on Jan. 4, 2012.

Grunsfeld currently serves as the deputy director of the Space Telescope Science Institute in Baltimore, which manages the science program for the Hubble Space Telescope and is a partner in the forthcoming James Webb Space Telescope. His background includes research in high energy astrophysics, cosmic ray physics and in the emerging field of exoplanet studies with specific interest in future astronomical instrumentation.

As a scientist, as well as a veteran of five space shuttle flights, Grunsfeld brings a unique viewpoint to the science directorate, and supporters are hoping for an increased association of science and human missions. “John’s understanding of the critical connection between scientific research and the human exploration of space makes him an ideal choice for this job,” NASA Administrator Charles Bolden said. “I look forward to working with him to take the agency’s science programs to even greater heights and make more of the ground-breaking discoveries about Earth and our universe for which NASA is known.”

Three of Grunsfeld’s flights were Hubble telescope repair missions, and he performed a total of eight spacewalks to service and upgrade the observatory. Additionally, in 2004 and 2005, Grunsfeld served as the commander and science officer on the backup crew for Expedition 13 to the International Space Station.

Read more about Grunsfeld here.

Posted on by Nancy Atkinson

Carl Sagan’s Influence: Favorite Quotes from Readers

Today would have been Carl Sagan’s 77th birthday, and the past few years November 9th has been designated as “Carl Sagan Day” by people who appreciate Sagan’s influence — not only on science, but also the public’s understanding of it. We asked our readers to share their favorite Saganese: their most cherished quotes from the man who has inspired many. Here are our readers’ favorite quotes, images and videos:

F Alejandro Espinosa, @Tadeo_Meneo, @Otto J. Mäkelä, Brad Goodspeed – “Somewhere, something incredible is waiting to be known.” Thilina Heenatigala said of this quote, “As a kid I loved this quote, it gives the feeling of wanting to know more, to discover our Universe.”

Anthony Collini – “I’m not very good at singing songs, but here’s a try…whoop, bow…”

Christine Reece – This quote seems to apply to us more and more: “Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works.” I’m frustrated by all the attempts to remove science from classrooms in the U.S. Our children deserve and need better from us.

Dan Dalessio – “Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people.”

Robert Goodwin – “All civilizations become either spacefaring or extinct.”

Silex Anthropos – “It is of interest to note that while some dolphins are reported to have learned English – up to fifty words used in correct context – no human being has been reported to have learned dolphinese.”

The 13.7 billion year lifetime of the universe mapped onto a single year. This image helps to put cosmology, evolution, and written history in context. In addition to dates of important events, dates for availability for different types of evidence are shown. From the series, 'Cosmos.'

Beth Perry Steger – It is not a quote but a calendar he displayed in the Cosmos series. It shows the Big Bang on Jan 1. Throughout the year he demonstrates when planets formed, when Earth became habitable, and in December it shows people came to be. It gives a sense of the vast history of our solar system and how “new” homo sapiens came into the picture.

Esther Porter, Damian Lima – “Some part of our being knows this is where we came from. We long to return. And we can. Because the cosmos is also within us. We’re made of star-stuff. We are a way for the cosmos to know itself.”

Adnan Yousuf – “But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright Brothers. But they also laughed at Bozo the Clown.”

Don Davis – “I don’t want to believe, I want to know”

Amy Fredericks, Yuri Aviani – “If you want to make an apple pie from scratch, you must first invent the Universe.”

Linda Lee – “The sky calls to us. If we do not destroy ourselves, we will one day, venture to the stars.” These quotes are important to me because he was able to speak passionate words into my little world, help me think bigger than just my immediate surroundings, look up, and embrace the Universe.

Nathan Shickle, Nathan Mickelson, – “It is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.” Heather Archuletta said this quote was special to her: Because he cared more for truth and wisdom than anyone I had ever seen on TV, and I am so grateful he lived in an age where he couldn’t be burned at the stake for embracing reality.

@Osiriscombe Sam – “Imagination will often carry us to worlds that never were. But without it we go nowhere.”

Tracey Robinson – “…we will one day venture to the stars.

@TabletopExplainer – “Extraordinary claims require extraordinary evidence.”

Raúl Alva – “Science is much more a way of thinking than it is a body of knowledge.”

Joe Rhea – “It’s perilous and foolhardy for the average citizen to remain ignorant about global warming, say, or ozone depletion, air pollution, toxic and radioactive wastes, acid rain, topsoil erosion, tropical deforestation, exponential population growth. Jobs and wages depend on science and technology.”

@NextStepinSpace suggested a video that we posted last week about “The Gift of Apollo”

And you can read a post from Fraser on the influence Carl Sagan had on his life, including the inspiration to start Universe Today.

I count myself among those who say they might not be where they are today were it not for Carl Sagan. Reading his books such as “Cosmos” and “Demon Haunted World” broadened my horizons when I needed it most. One of my favorite books of all time is “Pale Blue Dot” which really puts everything in perspective.