Density Puts Things In Their Proper Places.

(Causus maculatus) -  Common names include forest rhombic night adder, West African night adder and spotted night adder.

December 13, 1965 – Truly spectacular images of our planet captured by the astronauts of Gemini 7 as they zoomed around the Earth. In this era when we receive a daily dose of awesomeness from hi-res cameras on the ISS and various satellites, it’s easy to take beautiful Earth images for granted. I will never cease to be amazed by the stunning photography produced during the Project Gemini missions.

(NASA/Arizona State University)

Comet Lovejoy is visible near Earth’s horizon in this nighttime image photographed by NASA astronaut Dan Burbank, Expedition 30 commander, onboard the International Space Station on Dec. 21, 2011.

Image credit: NASA

This image shows an artist’s impression of the 10 Hot Jupiter Exoplanets studied using the Hubble and Spitzer Space Telescopes. From the upper left to the lower right corner, these planets are WASP-12b, WASP-6b, WASP-31b, WASP-39b, HD 189733b, HAT-P-12b, WASP-17b, WASP-19b, HAT-P-1b And HD 209458b.

Credit: ESA / Hubble & NASA

Composed of gas and dust, the pictured pillar resides in a tempestuous stellar nursery called the Carina Nebula, located 7500 light-years away in the southern constellation of Carina.

Credit: NASA, ESA and the Hubble SM4 ERO Team

Black Holes are not so Black (Part 3) - Gravitational Waves

The existence of Gravitational Waves have been confirmed. But you probably have heard that. In this post, we will break down this profound discovery into comprehend-able chunks.

This is going to be a amazing journey. Ready ?

Redefining Gravity

When we usually talk of Gravitation we are bound to think like Newton, where objects are assumed to exerting a force upon each other.

Like imaginary arrows of force in space. But this picture, although good for high school crumbled, with the advent of Einstein’s theory of Relativity.

What is the Space-Time Fabric?

Think of space-time fabric as an actual cloth of fabric. ( An analogy )

When you place an object on the fabric, the cloth curves. This is exactly what happens in the solar system as well.

The sun with such a huge mass bends the space-time fabric. And the earth and all the planets are kept in orbit by following this curvature that has been made by the sun.

Attributing to the various masses of objects, the way they bend this fabric also varies.

What are Gravitational Waves?

If you drop an object in a medium such as water, they produce ripples that propagate as waves through the medium.

Similarly, Gravitational waves are ripples in space-time fabric produced when you drag heavy objects through space time.

And the nature of these waves is that they don’t require a medium to propagate.

How do you make one?

Everything with mass/energy can create these waves.

Source

Two persons dancing around each other in space too can create gravitational waves. But the waves would be extremely faint.

You need something big and massive accelerating through space-time in order to even detect them.

And orbiting binary stars/black holes are valuable in this retrospect.

How can you detect them?

Let’s turn to the problem to detecting them assuming you do find binary stars/black-holes in the wondrous space to suite your needs.

Well, for starters you cannot use rocks/ rulers to measure them because as the space expands and contracts, so do the rocks. ( the distances will remain same in both the cases )

Here’s where the high school fact that the speed of Light is a constant no matter what plays an important and pivotal role.

If the space expands, the time taken for light to reach from A to B would be longer. And if it contracts, the time taken for it to reach from A to B would be smaller.

PC: PHDComics

By allowing the light waves from the contraction and expansion to interfere with each other, such as done in any interferometry experiment we can detect the expansion or contraction. Voila!

And this is exactly what they did! ( on a macroscopic level ) at LIGO (Laser Interferometer Gravitational-Wave Observatory)

14 September 2015

Two Black Holes with masses of 29 and 36 solar masses merged together some 1.3 Billion light years away.

Two Black Holes colliding is the header animation of the ‘Black Holes are not so Black Series’, in case if you haven’t noticed.

The merger of these two black holes results in the emission of energy equivalent to 3 solar masses as Gravitational Waves.

This signal was seen by both LIGO detectors, in Livingston and Hanford, with a time difference of 7 milliseconds.

And with the measurement of this time difference, physicists have pronounced the existence of Gravitational Waves.

Source

All this is most certainly easily said than done and requires meticulous and extensive research, not to mention highly sensitive instruments.

Had they not have measured this time difference, we might have had to wait for the merger for more massive black holes to collide and maybe even build more sensitive instruments to detect these waves.

And Einstein predicted this a 100 years back!

Mind Blown!

Note: Hope you are able to understand and appreciate the profundity of the discovery done by mankind.

** All animations used here are merely for Educational purposes. If you have any issues, please write to us at : 153armstrong@gmail.com

Curiosity Rover: Five Years on Mars

The evening of August 5, 2012…five years ago…our Mars Curiosity rover landed on the Red Planet. 

Arriving at Mars at 10:32 p.m. PDT (morning of Aug 6 EDT), this rover would prove to be the most technologically advanced rover ever built.

Curiosity used a series of complicated landing maneuvers never before attempted. 

The specialized landing sequence, which employed a giant parachute, a jet-controlled descent vehicle and a daring “sky crane” maneuver similar to rappelling was devised because testing and landing techniques used during previous rover missions could not safely accommodate the much larger and heavier rover.

Curiosity’s mission: To determine whether the Red Planet ever was, or is, habitable to microbial life.

The car-size rover is equipped with 17 cameras, a robotic arm, specialized instruments and an on-board laboratory.

Let’s explore Curiosity’s top 5 discoveries since she landed on Mars five years ago…

1. Gale Crater had conditions suitable for life about 3.5 billion years ago

In 2013, Curiosity’s analysis of a rock sample showed that ancient Mars could have supported living microbes. Scientists identified sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon – some of the key chemical ingredients for life – in the powder Curiosity drilled out of a sedimentary rock near an ancient stream bed in Gale Crater.

Later, in 2014, Curiosity discovered that these conditions lasted for millions of years, perhaps much longer. This interpretation of Curiosity’s findings in Gale Crater suggests ancient Mars maintained a climate that could have produced long-lasting lakes at many locations on the Red Planet.

2. Organic molecules detected at several locations

In 2014, our Curiosity rover drilled into the Martian surface and detected different organic chemicals in the rock powder. This was the first definitive detection of organics in surface materials of Mars. These Martian organics could either have formed on Mars or been delivered to Mars by meteorites. 

Curiosity’s findings from analyzing samples of atmosphere and rock powder do not reveal whether Mars has ever harbored living microbes, but the findings do shed light on a chemically active modern Mars and on favorable conditions for life on ancient Mars.

3. Present and active methane in Mars’ atmosphere

Also in 2014, our Curiosity rover measured a tenfold spike in methane, an organic chemical, in the atmosphere around the planet. This temporary increase in methane tells us there must be some relatively localized source.

Researchers used Curiosity’s onboard Sample Analysis at Mars (SAM) laboratory a dozen times in a 20-month period to sniff methane in the atmosphere. During two of those months, in late 2013 and early 2014, four measurements averaged seven parts per billion.

4. Radiation could pose health risks for humans

Measurements taken by our Curiosity rover since launch have provided us with the information needed to design systems to protect human explorers from radiation exposure on deep-space expeditions in the future. Curiosity’s Radiation Assessment Detector (RAD) was the first instrument to measure the radiation environment during a Mars cruise mission from inside a spacecraft that is similar to potential human exploration spacecraft.

The findings indicate radiation exposure for human explorers could exceed our career limit for astronauts if current propulsion systems are used. These measurements are being used to better understand how radiation travels through deep space and how it is affected and changed by the spacecraft structure itself. This, along with research on the International Space Station are helping us develop countermeasures to the impacts of radiation on the human body.

5. A thicker atmosphere and more water in Mars past

In 2015, Curiosity discovered evidence that has led scientists to conclude that ancient Mars was once a warmer, wetter place than it is today. 

To produce this more temperate climate, several researchers have suggested that the planet was once shrouded in a much thicker carbon dioxide atmosphere. You may be asking…Where did all the carbon go?

The solar wind stripped away much of Mars’ ancient atmosphere and is still removing tons of it every day. That said, 3.8 billion years ago, Mars might have had a moderately dense atmosphere, with a surface pressure equal to or less than that found on Earth.

Our Curiosity rover continues to explore the Red Planet today. On average, the rover travels about 30 meters per hour and is currently on the lower slope of Mount Sharp.

Get regular updates on the Curiosity mission by following @MarsCuriosity on Twitter.

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What’s Up November 2017

What’s Up For November?

Dawn pairing of Jupiter and Venus, Moon shines near star clusters, meteor activity all month long!

This month binoculars will come in handy–to view the moon, star clusters, and a close pairing of Venus and Jupiter.

You can’t miss bright Venus in the predawn sky. This month Venus pairs up with Jupiter on the morning of November 13th.

The Leonids peak on a moonless November 17th. Expect no more than 10 meteors an hour around 3:00 a.m., the height of the shower.

The Northern and Southern sub-branches of the Taurid meteor shower offer sparse counts of about 5 meteors per hour, but slow, bright meteors are common.

The nearby November Orionids peak on the 28th. In contrast to the Taurids, the Orionids are swift. But don’t expect more than 3 meteors per hour.

The moon glides by three beautiful star clusters in the morning sky this month, and a pair of binoculars will allow you to see the individual stars in the clusters. Aim your binoculars at the Pleiades and the moon on the 5th.

Then aim at the Messier or M-35 cluster and the moon on the 7th and the Beehive cluster and the moon on the 10th.

Meanwhile, at dusk, catch Saturn as it dips closer to the western horizon and pairs up with Mercury on the 24th through the 28th.

Also, Comet C/2017 O1 should still be a binocular-friendly magnitude 7 or 8 greenish object in November. Use Polaris, the North Star as a guide. Look in the East to Northeast sky in the late evening.  

Watch the full What’s Up for November Video: 

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.  

Solar System: 10 Things to Know This Week

Need some space? 

Here are 10 perspective-building images for your computer desktop and mobile device wallpaper. 

These are all real images, sent very recently by our planetary missions throughout the solar system. 

1. Our Sun

Warm up with this view from our Solar Dynamics Observatory showing active regions on the Sun in October 2017. They were observed in a wavelength of extreme ultraviolet light that reveals plasma heated to over a million degrees. 

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2. Jupiter Up-Close

This series of enhanced-color images shows Jupiter up close and personal, as our Juno spacecraft performed its eighth flyby of the gas giant planet on Sept. 1, 2017. 

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3. Saturn’s and Its Rings

With this mosaic from Oct. 28, 2016, our Cassini spacecraft captured one of its last looks at Saturn and its main rings from a distance. 

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4. Gale Crater on Mars

This look from our Curiosity Mars rover includes several geological layers in Gale crater to be examined by the mission, as well as the higher reaches of Mount Sharp beyond. The redder rocks of the foreground are part of the Murray formation. Pale gray rocks in the middle distance of the right half of the image are in the Clay Unit. A band between those terrains is “Vera Rubin Ridge,” where the rover is working currently. The view combines six images taken with the rover’s Mast Camera (Mastcam) on Jan. 24, 2017. 

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5. Sliver of Saturn

Cassini peers toward a sliver of Saturn’s sunlit atmosphere while the icy rings stretch across the foreground as a dark band on March 31, 2017. This view looks toward the unilluminated side of the rings from about 7 degrees below the ring plane. 

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6. Dwarf Planet Ceres 

This image of the limb of dwarf planet Ceres shows a section of the northern hemisphere, as seen by our Dawn mission. Prominently featured is Occator Crater, home of Ceres’ intriguing “bright spots.” The latest research suggests that the bright material in this crater is comprised of salts left behind after a briny liquid emerged from below. 

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7. Martian Crater

This image from our Mars Reconnaissance Orbiter (MRO) shows a crater in the region with the most impressive known gully activity in Mars’ northern hemisphere. Gullies are active in the winter due to carbon dioxide frost, but northern winters are shorter and warmer than southern winters, so there is less frost and less gully activity. 

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8. Dynamic Storm on Jupiter

A dynamic storm at the southern edge of Jupiter’s northern polar region dominates this Jovian cloudscape, courtesy of Juno. This storm is a long-lived anticyclonic oval named North North Temperate Little Red Spot 1. Citizen scientists Gerald Eichstädt and Seán Doran processed this image using data from the JunoCam imager. 

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9. Rings Beyond Saturn’s Sunlit Horizon 

This false-color view from the Cassini spacecraft gazes toward the rings beyond Saturn’s sunlit horizon. Along the limb (the planet’s edge) at left can be seen a thin, detached haze. 

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10. Saturn’s Ocean-Bearing Moon Enceladus

Saturn’s active, ocean-bearing moon Enceladus sinks behind the giant planet in a farewell portrait from Cassini. This view of Enceladus was taken by NASA’s Cassini spacecraft on Sept. 13, 2017. It is among the last images Cassini sent back before its mission came to an end on Sept. 15, after nearly 20 years in space. 

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Applying Wallpaper: 1. Click on the screen resolution you would like to use. 2. Right-click on the image (control-click on a Mac) and select the option ‘Set the Background’ or 'Set as Wallpaper’ (or similar).

Places to look for more of our pictures include solarsystem.nasa.gov/galleries, images.nasa.gov and www.jpl.nasa.gov/spaceimages.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Chasing the Shadow of Neptune’s Moon Triton

Our Flying Observatory

Our flying observatory, called SOFIA, carries a 100-inch telescope inside a Boeing 747SP aircraft. Scientists onboard study the life cycle of stars, planets (including the atmosphere of Mars and Jupiter), nearby planetary systems, galaxies, black holes and complex molecules in space.

AND in just a few days SOFIA is going on a special flight to chase the shadow of Neptune’s moon Triton as it crosses Earth’s surface!

In case you’re wondering, SOFIA stands for: Stratospheric Observatory for Infrared Astronomy.

Triton

Triton is 1,680 miles (2,700 km) across, making it the largest of the 13 moons orbiting Neptune. Unlike most large moons in our solar system, Triton orbits in the opposite direction of Neptune, called a retrograde orbit. This backward orbit leads scientists to believe that Triton formed in an area past Neptune, called the Kuiper Belt, and was pulled into its orbit around Neptune by gravity. 

The Voyager 2 spacecraft flew past Neptune and Triton in 1989 and found that Triton’s atmosphere is made up of mostly nitrogen…but it has not been studied in nearly 16 years!

Occultations are Eclipse-Like Events

An occultation occurs when an object, like a planet or a moon, passes in front of a star and completely blocks the light from that star. As the object blocks the star’s light, it casts a faint shadow on Earth’s surface. 

But unlike an eclipse, these shadows are not usually visible to the naked eye because the star and object are much smaller and not nearly as bright as our sun. Telescopes with special instruments can actually see these shadows and study the star’s light as it passes near and around the object – if they can be in the right place on Earth to catch the shadow.

Chasing Shadows

Scientists have been making advanced observations of Triton and a background star. They’ve calculated exactly where Triton’s faint shadow will fall on Earth! Our SOFIA team has designed a flight path that will put SOFIA (the telescope and aircraft) exactly in the center of the shadow at the precise moment that Triton and the star will align. 

This is no easy feat because the shadow is moving at more than 53,000 mph while SOFIA flies at Mach 0.85 (652 mph), so we only have about two minutes to catch the shadow!! But our SOFIA team has previously harnessed the aircraft’s mobility to study Pluto from inside the center of its occultation shadow, and is ready to do it again to study Triton!

What We Learn From Inside the Shadow

From inside the shadow, our team on SOFIA will study the star’s light as it passes around and through Triton’s atmosphere. This allows us to learn more about Triton’s atmosphere, including its temperature, pressure, density and composition! 

Our team will use this information to examine if Triton’s atmosphere has changed since our Voyager 2 spacecraft flew past it in 1989. That’s a lot of information from a bit of light inside a shadow! Similar observations of Uranus in 1977, from our previous flying observatory, led to the discovery of rings around that planet!

International Ground-Based Support

Ground-based telescopes across the United States and Europe – from Scotland to the Canary Islands – will also be studying Triton’s occultation. Even though most of these telescopes will not be in the center of the shadow, the simultaneous observations, from different locations on Earth, will give us information about how Triton’s atmosphere varies across its latitudes. 

This data from across the Earth and from onboard SOFIA will help researchers understand how Triton’s atmosphere is distorted at different locations by its high winds and its strong tides!

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.