is video shows a simulation of the space environment all the way out to Pluto in the months surrounding New Horizons’ July 2015 flyby. At the time, scientists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, worked with the New Horizons team to test how well their models—and other models contributed by scientists around the world—predicted the space environment at Pluto. Understanding the environment through which our spacecraft travel can ultimately help protect them from radiation and other potentially damaging effects. Visualizers at Goddard recently updated the movie of the model, creating this new release.
Though the vacuum of space is about a thousand times emptier than a laboratory vacuum, it’s still not completely empty. The sun releases a constant stream of particles called the solar wind—as well as occasional denser clouds of particles known as coronal mass ejections, or CMEs—both containing embedded magnetic fields. The density, speed, and temperature of these particles, as well as the direction and strength of the embedded magnetic fields, make up the space environment.
To map the space environment at Pluto, scientists combined the predictions of several models—and looked at events that had long since passed Earth.
"We set the simulation to start in January of 2015, because the particles passing Pluto in July 2015 took some six months to make the journey from the sun," said Dusan Odstrcil, a space weather scientist at Goddard who created the Enlil model. The Enlil model, named for the Sumerian god of the wind, is one of the primary models used to simulate the space environment near Earth and is the basis for the New Horizons simulation.
The new, combined model tracks CMEs longer than ever before. Because particles must travel for many months before reaching Pluto, the CMEs eventually spread out and merge with other CMEs and the solar wind to form larger clouds of particles and magnetic field. These combined clouds stretch out as they travel away from the sun, forming thin ring shapes by the time they reach Pluto—quite different from the typical balloon shape of CMEs seen here at Earth.
Source: NASA press release
When it comes to objects and force, Isaac Newton’s Three Laws of Motion are pretty straightforward. Apply force to an object in a specific direction, and the object will move in that direction. And unless there’s something acting against it (like gravity or air pressure) it will keep moving in that direction until something stops it. But when it comes to “negative mass”, the exact opposite is true.
According to the Nebula Hypothesis, stars and their systems of planets form from giant clouds of dust and gas. After undergoing gravitational collapse at the center (which creates the star), the remaining matter then forms an accretion disk in orbit around it. Over time, this matter is fed to the star – allowing it to become more massive – and also leads to the creation of a system of planets.
If we want to send spacecraft to exoplanets to search for life, we better get good at building submarines.
It is good time to be an exoplanet hunter… or just an exoplanet enthusiast for that matter! Every few weeks, it seems, new discoveries are being announced which present more exciting opportunities for scientific research. But even more exciting is the fact that every new find increases the likelihood of locating a potentially habitable planet (and hence, life) outside of our Solar System.
There was much excitement when NASA recently revealed new details about the oceans that lurk beneath the surface of Saturn’s tiny moon Enceladus and Jupiter’s Europa. Why the excitement? Well, here on Earth, where you have water, energy and nutrients, you have life. So why not life on these other worlds?
Saturn’s largest Moon, Titan, is the only other world in our Solar System that has stable liquid on its surface. That alone, and the fact that the liquid is composed of methane, ethane, and nitrogen, makes it an object of fascination. The bright spot features that Cassini observed in the methane seas that dot the polar regions only deepen the fascination.
In celebration of the 27th anniversary of the launch of NASA's Hubble Space Telescope on April 24, 1990, astronomers used the legendary telescope to take a portrait of a stunning pair of spiral galaxies. This starry pair offers a glimpse of what our Milky Way galaxy would look like to an outside observer.
Forty years ago, Canadian physicist Bill Unruh made a surprising prediction regarding quantum field theory. Known as the Unruh effect, his theory predicted that an accelerating observer would be bathed in blackbody radiation, whereas an inertial observer would be exposed to none. What better way to mark the 40th anniversary of this theory than to consider how it could affect human beings attempting relativistic space travel?
When the Apollo astronauts returned to Earth, they came bearing 380.96 kilograms (839.87 lb) of Moon rocks. From the study of these samples, scientists learned a great deal about the Moon’s composition, as well as its history of formation and evolution. For example, the fact that some of these rocks were magnetized revealed that roughly 3 billion years ago, the Moon had a magnetic field.
NASA strives to explore space and to expand our understanding of our Solar System and beyond. But they also turn their keen eyes on Earth in an effort to understand how our planet is doing. Now, they’re releasing a new composite image of Earth at night, the first one since 2012.