From NASA Heliophysics. The number of sunspots increases and decreases over time in a regular, approximately 11-year cycle, called the sunspot cycle. The exact length of the cycle can vary. It has been as short as eight years and as long as fourteen, but the number of sunspots always increases over time, and then returns to low again.
More sunspots mean increased solar activity, when great blooms of radiation known as solar flares or bursts of solar material known as coronal mass ejections (CMEs) shoot off the sun’s surface. The highest number of sun spots in any given cycle is designated “solar maximum,” while the lowest number is designated “solar minimum.” Each cycle, varies dramatically in intensity, with some solar maxima being so low as to be almost indistinguishable from the preceding minimum.
Sunspots are a magnetic phenomenon and the entire sun is magnetized with a north and a south magnetic pole just like a bar magnet. The comparison to a simple bar magnet ends there, however, as the sun’s interior is constantly on the move.
Excerpt from “Mysteries of a Dark Universe.” Albert Einstein sought to explain why the gravity of all the stars and gas out there didnt simply cause the universe to collapse into a heap. Following the discovery of the expanding universe, he admitted to the “greatest blunder” of his career.
The Mars Science Lab was launched November 26, 2011, and is scheduled to land on Mars at Gale Crater on August 6, 2012. The rover Curiosity, after completing a more precise landing than ever attempted previously, is intended to help assess Mars’ habitability for future human missions. Its primary mission objective is to determine whether Mars is or has ever been an environment able to support life.
Curiosity is five times as large as either of the Mars Exploration Rovers Spirit or Opportunity and carries more than ten times the mass of scientific instruments present on the older vehicles. The rover is expected to operate for at least 686 days as it explores with greater range than any previous Mars rover. Here are some of the specs that help set Curiosity apart from the other rovers:
The rover Curiosity is 3 meters in length, and weighs 900 kg, including 80 kg worth of scientific instruments. It is approximately the size of a Mini Cooper automobile.
Black hole extravaganza from ESOcast. Not long ago, watching something being ripped apart as it falls towards a giant black hole would be science fiction. This is now reality.
Observers under dark skies, far from the bright city lights, can marvel at the splendor of the Milky Way, arching in an imposing band across the sky. Zooming in towards the center of our galaxy, about 25000 light years away, you can see that it is composed of myriads of stars.
This is a pretty impressive sight, but much is hidden from view by interstellar dust, and astronomers need to look using a different wavelength, the infrared, that can penetrate the dust clouds. With large telescopes, astronomers can then see in detail the swarm of stars circling the supermassive black hole, in the same way that the Earth orbits the Sun.
The Galactic Center harbors the closest supermassive black hole known, and the one that is also the largest in terms of its angular diameter on the sky, making it the best choice for a detailed study of black holes.
EsoCast showcases a new Hubble image of a giant cloud of hydrogen gas illuminated by a bright young star. The image shows how violent the end stages of the star formation process can be, with the young object shaking up its stellar nursery.
A few thousand light-years away, in the constellation of Cygnus, lies the compact star-forming region Sh 2-106, or S106 for short. Despite the celestial colors of this picture, there is nothing peaceful about this scene. A young star, named S106 IR, is being born at the heart of the nebula. In the violent final stages of its formation, the star is ejecting material at high speed, violently disrupting the gas and dust. 3D visualizations show the extent to which the star has carved its surroundings into a complex shape. In particular, the hourglass-like structure of the nebula is a result of jets from the star slamming into the cloud of hydrogen it is forming from.
These high-res time-lapse sequences captured by astronauts aboard the International Space Station give us a beautiful and clear view of some well-known coastlines and countries around the world. Get a good look at England, France, Italy, Egypt, Algeria, Tunisia, Greece, the island of Crete, Taiwan, South Korea, Japan, the United States, Mexico, Ecuador, Peru, Chile, Argentina, Cuba, and more. We’ve attempted to show as many countries as we would, but inevitably we’ve left many out. Please write to the the astronaut photography office at NASA’s Johnson Space Center to request inclusion in this amazing series of sequences.
From EsoCast, Dr. J. explores the upheaval in our understanding of the universe brought on by the discovery that the universe is not just expanding, but is accelerating outward at an ever increasing pace. Was Einstein wrong? Are we missing something crucial in our understanding of how it all began? Either way, this is one of the most exciting scientific discoveries in a long time.
Take a breathtaking journey into the future, five billion years from now, to see the ultimate fate of the Solar System. This gem from HubbleCast showcases stunning Hubble imagery of the death throes of Sun-like stars. The wreckage of these dying stars form the building blocks of new generations of stars.
The Mars rover Opportunity was supposed to last three months. It’s now going on Nine Years. It’s proved so durable that in 2011 it was essentially sent on a whole new mission.
Opportunity reached a multi-year driving destination, Endeavour Crater, in August 2011. At Endeavour’s rim, it has gained access to geological deposits from an earlier period of Martian history than anything it examined during its first seven years. It also has begun an investigation of the planet’s deep interior that takes advantage of staying in one place for the Martian winter.
Opportunity landed in Eagle Crater on Mars on Jan. 25, 2004, Universal Time and EST (Jan. 24, PST), three weeks after its rover twin, Spirit, landed halfway around the planet. In backyard-size Eagle Crater, Opportunity found evidence of an ancient wet environment. The mission met all its goals within the originally planned span of three months. During most of the next four years, it explored successively larger and deeper craters, adding evidence about wet and dry periods from the same era as the Eagle Crater deposits.
Coming soon to “Cosmic Journeys.” Earth, over its 4.5 billion year history, has been pummeled by asteroids, eroded by wind and rain, covered over with flowing lava, wrinkled and gouged by shifts in its crust.
Most traces of its distant past have long since been destroyed. But there is a place where clues to the early history of our planet are still largely intact.
Scientists have been reconstructing its history by scouring its surface, mapping its mountains and craters, and probing its interior regions.
What are they learning about our own planet’s beginnings, by going back in time, to the mysterious “Birth of the Moon.”