A magnificent moon looms large over the Space Shuttle Columbia at Cape Canaveral, 1981.
NASA & ESA - Cassini-Huygens Mission to Saturn & Titan patch. Feb. 6, 2017
Seen from outside, Enceladus appears to be like most of its sibling moons: cold, icy and inhospitable. But under that forbidding exterior may exist the very conditions needed for life. Over the course of the Cassini mission, observations have shown that Enceladus (313 miles or 504 kilometers across) not only has watery jets sending icy grains into space; under its icy crust it also has a global ocean, and may have hydrothermal activity as well. Since scientists believe liquid water is a key ingredient for life, the implications for future missions searching for life elsewhere in our solar system could be significant. This view looks toward the Saturn-facing hemisphere of Enceladus. North on Enceladus is up and rotated 6 degrees to the right. The image was taken in green light with the Cassini spacecraft narrow-angle camera on Nov. 27, 2016. The view was obtained at a distance of approximately 81,000 miles (130,000 kilometers) from Enceladus. Image scale is 2,566 feet (782 meters) per pixel.
Cassini spacecraft around Saturn
The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org and http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens Images, Text, Credits: NASA/JPL-Caltech/Space Science Institute/Tony Greicius. Best regards, Orbiter.ch Full article
Early astronomers faced an obstacle: their technology. These great minds only had access to telescopes that revealed celestial bodies shining in visible light. Later, with the development of new detectors, scientists opened their eyes to other types of light like radio waves and X-rays. They realized cosmic objects look very different when viewed in these additional wavelengths. Pulsars — rapidly spinning stellar corpses that appear to pulse at us — are a perfect example.
The first pulsar was observed 50 years ago on August 6, 1967, using radio waves, but since then we have studied them in nearly all wavelengths of light, including X-rays and gamma rays.
Most pulsars form when a star — between 8 and 20 times the mass of our sun — runs out of fuel and its core collapses into a super dense and compact object: a neutron star.
These neutron stars are about the size of a city and can rotate slowly or quite quickly, spinning anywhere from once every few hours to hundreds of times per second. As they whirl, they emit beams of light that appear to blink at us from space.
One day five decades ago, a graduate student at the University of Cambridge, England, named Jocelyn Bell was poring over the data from her radio telescope - 120 meters of paper recordings.
Image Credit: Sumit Sijher
She noticed some unusual markings, which she called “scruff,” indicating a mysterious object (simulated above) that flashed without fail every 1.33730 seconds. This was the very first pulsar discovered, known today as PSR B1919+21.
Before long, we realized pulsars were far more complicated than first meets the eye — they produce many kinds of light, not only radio waves. Take our galaxy’s Crab Nebula, just 6,500 light years away and somewhat of a local celebrity. It formed after a supernova explosion, which crushed the parent star’s core into a neutron star.
The resulting pulsar, nestled inside the nebula that resulted from the supernova explosion, is among the most well-studied objects in our cosmos. It’s pictured above in X-ray light, but it shines across almost the entire electromagnetic spectrum, from radio waves to gamma rays.
Speaking of gamma rays, in 2015 our Fermi Gamma-ray Space Telescope discovered the first pulsar beyond our own galaxy capable of producing such high-energy emissions.
Located in the Tarantula Nebula 163,000 light-years away, PSR J0540-6919 gleams nearly 20 times brighter in gamma-rays than the pulsar embedded in the Crab Nebula.
No two pulsars are exactly alike, and in 2013 an especially fast-spinning one had an identity crisis. A fleet of orbiting X-ray telescopes, including our Swift and Chandra observatories, caught IGR J18245-2452 as it alternated between generating X-rays and radio waves.
Scientists suspect these radical changes could be due to the rise and fall of gas streaming onto the pulsar from its companion star.
This just goes to show that pulsars are easily influenced by their surroundings. That same year, our Fermi Gamma Ray Space Telescope uncovered another pulsar, PSR J1023+0038, in the act of a major transformation — also under the influence of its nearby companion star.
The radio beacon disappeared and the pulsar brightened fivefold in gamma rays, as if someone had flipped a switch to increase the energy of the system.
Our Neutron star Interior Composition Explorer (NICER) mission, launched this past June, will study pulsars like those above using X-ray measurements.
With NICER’s help, scientists will be able to gaze even deeper into the cores of these dense and mysterious entities.
For more information about NICER, visit https://www.nasa.gov/nicer
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
1981 NASA diagram gives a cutaway view inside a space shuttle.
“Dear God, please don’t let me fuck up.”
—Alan Shepard
45 YEARS AGO TODAY: The Apollo 16 mission blasts off from Cape Canaveral on April 16, 1972.
The Moon - Incredible Lunar Views From The Japanese SELENE Orbiter - Earthrise
Inmarsat-5 F4 successfully launched from LC-39A at Kennedy Space Center at 7:21pm EDT May 15. The Falcon 9 deployed the satellite into Geostationary Transfer Orbit 31 minutes and 48 seconds after liftoff. Since the rocket was flying in its expandable configuration, following main engine cutoff the first stage fell into the Atlantic ocean and was not recovered. The launch of the Inmarsat mission marked the first time SpaceX began testing countdown procedures for their next major upgrade of the Falcon 9 rocket, the Block IV. Normally, the rocket’s liquid oxygen propellant is loaded into the rocket 45 minutes before launch, ten minutes after RP-1. For Inmarsat, the LOX was loaded 35 minutes before liftoff. The Block IV variant will see this procedure occur during every countdown. Check out or Inmarsat-5 F4 launch archive here.
P/c: SpaceX.
Solar System
via reddit