Solar System

The sun and its solar system are moving through the universe significantly more slowly than astronomers had previously believed, too slowly to generate the bow shock wave that researchers had thought preceded it. The bow shock wave, much like the sonic boom that accompanies an aircraft traveling at supersonic speeds, occurs when particles in gas clouds cannot get out of the way fast enough, and has been routinely demonstrated in images of other...

NASA'sfirst hard look at the protoplanet Vesta has given scientists an unprecedented view of its makeup, terrain and history - and revealed that major activity on this ancient rock occurred far more recently than researchers had expected. Images sent back from NASA's trailblazing Dawn spacecraft reveal the full size of a massive crater in the southern hemisphere and indicate that it may have been made just 1 billion years ago, well after Vesta formed more than 4.5 billion years ago, according to one of half a dozen studies published in Friday's edition of the journal Science.

The chest-high rack of electronics Justin Kasper is assembling in a Massachusetts office park will fit in a shoe box before he's done. It won't be much to look at - a few inches across, shaped rather like a coffee cup attached to a Kindle - but to Kasper, it'll serve as eyes across nearly 100 million miles of space. In less than seven years, that cup will be journeying to the center of the solar system to scoop up bits of the sun. "This really has been a life's dream," said Kasper, of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.

When President John F. Kennedy announced in 1961 that America was committed to "landing a man on the moon and returning him safely to the Earth" by the end of the decade, winning the race became the paramount objective of the national space program. But UC San Diego nuclear chemist James R. Arnold played a crucial role in drawing official attention to another goal: preserving and studying the soil and rock samples that Apollo astronauts would bring back with them. Arnold, 88, who died Jan. 6 in La Jolla from complications of Alzheimer's disease, was a member of a group of four scientists — dubbed the Four Horsemen by colleagues — who sounded the alarms that led NASA to establish a program for analyzing what proved to be a treasure trove for lunar research.

At the Jet Propulsion Laboratory in La Cañada Flintridge, the New Year's celebration will have to wait - until 2:05 p.m. Sunday, to be exact. That's when the second of two NASA spacecraft is expected to enter the moon's orbit on a $496-million mission scientists hope will provide unprecedented insight into the interior composition of Earth's closest neighbor. On Saturday afternoon, the first satellite constituting the Gravity Recovery and Interior Laboratory successfully entered the moon's orbit after a 3 1/2-month trip from Earth.

Scientists have confirmed the existence of two Earth-sized, rocky planets orbiting a star called Kepler-20, 1,000 light-years away in the constellation Lyra. The planets are the smallest ever confirmed orbiting a sun-like star, and their discovery, reported Tuesday, is an important milestone for NASA's Kepler mission, which faces the technically daunting task of finding small, Earth-like worlds in faraway solar systems that may — or may not — have been able to sustain life in the past.

Get psyched, people of Earth: There's an asteroid headed our way. On Tuesday, the asteroid known as YU55 will come closer to our planet than any other asteroid has come since 1976. Of course, when it comes to outer space, "close" is a relative word. Scientists at the Jet Propulsion Laboratory in Pasadena say YU55 will come within 201,700 miles of Earth and no closer. That's nearer than we are to the moon, but far enough away to eliminate the possibility of a collision. "We know exactly where it is going to be, and we don't have any chance of impact for the following hundred years," Marina Brozovic, a scientist and member of the JPL Goldstone radar team, told The Times.

Eris, the dwarf planet whose 2005 discovery led to Pluto losing its status as a planet, has passed in front of a star, providing astronomers with the clearest view of it since it was identified. It is about the same size as Pluto and is one of the brightest objects in the solar system, according to the new analysis, released Wednesday by the journal Nature. Scientists' picture of Eris had remained fuzzy because its distance from Earth is so vast: It is about three times farther out from the sun than Pluto.

SolarCity, one of the country's largest residential solar energy system providers, plans to double the amount of rooftop installations across the country by setting up sun-powered systems on 160,000 homes and other buildings on military bases. The five-year, $1-billion SolarStrong project targets rooftop solar installations at 124 military housing developments in 33 states. SolarCity has already lined up a conditional commitment for a $344-million loan guarantee from the federal government.

Want to explore the solar system and follow NASA space missions in real time? NASA is giving the public the chance to do just that through a new Internet-based tool called Eyes on the Solar System. The space agency said the tool combines video game technology and NASA data to create an environment for users to ride along with agency spacecraft as they explore the cosmos. "You are now free to move about the solar system," Blaine Baggett, a manager at NASA's Jet Propulsion Laboratory in La Cañada Flintridge, said in a statement.