Articles

Emily Lakdawalla

Tomorrow is the 20th anniversary of the launch of the Hubble Space Telescope. It's hard to believe it's been going strong for so many years.

Emily Lakdawalla

This is just a brief note to advertise this evening's edition of NOVA on public television here in the U.S. The show is

Emily Lakdawalla

I just posted my writeup of today's press briefing on a new map of Pluto produced from Hubble images. The main conclusion was that Pluto has shown an astonishing amount of changes across its surface between 1994 and 2002 -- more, in fact, than any other solid surface in the solar system.

Ted Stryk

The New Horizons science team is meeting this week. Ted Stryk was invited to attend the meeting, and he sent the following notes from the first day.

Alan Stern

Despite still being more than six years and just over 18 Astronomical Units from the Pluto system, the project team for New Horizons is conducting the second and final portion of our Pluto Encounter Preliminary Design Review (EPDR) tomorrow and the next day.

Emily Lakdawalla

As New Horizons continues its journey (it's now approaching the orbital distance of Saturn, though it's very far from that planet in space), the mission is taking advantage of the recent experience with the Jupiter flyby to plan out the science operations for the Pluto-Charon encounter.

Emily Lakdawalla

I've just posted a news story on a recently published paper that suggests that Pluto's moon Charon may have active ice volcanoes.

Emily Lakdawalla

According to the mission website, the New Horizons spacecraft has drifted off to sleep, entering its

Emily Lakdawalla

Yesterday the New Horizons team released a flicker animation showing the spacecraft's first sight of Pluto, using the LORRI long-range imaging instrument.

Emily Lakdawalla

I received quite a number of emails containing suggested names for Pluto's moons -- thanks! I just sent all the suggestions to Alan Stern; here they are for everybody's enjoyment.

Emily Lakdawalla

I just posted today's installment of Planetary Radio, in which Mat Kaplan gets an update on New Horizons from Principal Investigator Alan Stern-- check it out!

Emily Lakdawalla

Since the discovery of 2003 UB313, larger than Pluto, there's been a lively debate going on in many places about what makes a planet. There's now an article in Nature talking about a proposal that would address the controversy

Amir Alexander

To mark the 75th anniversary of the discovery of the planet Pluto, The Planetary Society presents to its readers the remarkable story of the discovery.

Amir Alexander

74 years after Clyde Tombaugh discovered Pluto as a faint dot on a pair of photographic plates, a modern group of astronomers made another remarkable discovery. On March 15, 2004, Michael Brown of Caltech, Chad Trujillo of the Gemini Observatory, and David Rabinowitz of Yale announced the discovery of Sedna – the furthest object ever detected in the Solar System.

Amir Alexander

The discovery of Planet X was announced to the world on March 13, 1930, which marked the anniversary of William Herschel’s discovery of Uranus in 1781 as well as Percival Lowell’s birthday. The observatory’s communiqué emphasized that the discovery was no coincidence, but the vindication of Lowell’s predictions made years before.

Amir Alexander

Since his teenage years Clyde Tombaugh had been an avid amateur astronomer and a gifted telescope builder. Based on instructions contained in an article from a boy’s Sunday school paper, he built a series of telescopes of increasing power and quality on the family farm.

Amir Alexander

The discovery of Neptune accounted for nearly all the unexplained motions of the outer planets of the Solar System. Nevertheless, several astronomers insisted that some unexplained residual motions remained, pointing to the presence of a ninth planet beyond the orbit of Neptune.

Amir Alexander

Since humans first set their eyes to the stars, they noticed that a few of these bright objects behaved differently from the others. Whereas all the stars moved together, revolving around the Earth once every 24 hours, five appeared to move within the firmament among the other stars. Accordingly, they were named “planets,” meaning “wanderers” in Greek.

Amir Alexander

February 18, 1930, was a cloudy day at the Lowell Observatory, on top of Mars Hill in Flagstaff, Arizona. 22 year old Clyde Tombaugh was hard at work, peering through the lens of an ancient-looking brass-colored device. The instrument, known as a “blink comparator,” mounted two large photographic plates.