. 24/7 Space News .
Sundials On Earth And Mars Mark The Spring Equinox

This image composite highlights the Mars Exploration Rover Opportunity's "sweep" magnet, which scientists use to study the origins of dust in the atmosphere. The panoramic image below indicates the location of the magnet on the side of the rover's calibration target, or "martian sundial." The images above, also taken by the panoramic camera, show a close-up of the magnet and the dark ring that collects magnetic airborne particles. The bright hole in the center of the magnet repels magnetic particles, forcing them to land only on the outer ring. Non-magnetic particles are expected to settle on all parts of the magnet, including the center. Because this center hole remains clean, scientists have concluded that nearly all of the dust particles in Mars' atmosphere are magnetic. Image NASA/JPL/Cornell.
Los Angeles - Mar 16, 2004
An unexpected spinoff from the high-technology, high-precision Mars Exploration Rover mission is an Earthly educational project - EarthDials around the world.

On March 20th, The Planetary Society invites people worldwide to mark Earth's Spring Equinox with a vicarious trip around the globe to see these special sundials, called EarthDials.

The EarthDial Project is a growing worldwide network of sundials to show the passage of time the old-fashioned way by tracking the motion of the Sun across the sky. Volunteers at 14 sites in six countries have created their own sundials in conjunction with the two sundials ("MarsDials") currently traversing the Martian terrain on NASA's twin rovers Spirit and Opportunity.

The EarthDial Project is a partnership between The Planetary Society (the world's largest space interest group); Bill Nye, the Science Guy; and Professor Woody Sullivan at the University of Washington.

"Seeing live sundials around the world makes the variations of time on our planet more real in the minds of kids and adults, and does it in a fun way," said Planetary Society Director of Projects Bruce Betts. "Time zone maps can't convey Earth time the way EarthDials can."

The gently curved path that the Sun traces is quite different from England to Malaysia, and so, the angles and lines on every EarthDial are different. But on the Spring Equinox, the shadows of objects all over the Earth, including those cast on the EarthDials, will trace a straight line as the Sun rises exactly in the east and sets exactly in the west. Equinoxes occur twice a year in Spring and Autumn.

In principle, we might expect exactly 12 hours of daylight and 12 hours of darkness on the Equinox. However, the Earth's atmosphere scatters and bends sunlight, so that we get a bit more than 12 hours of daylight. For North America, the moment of the Spring Equinox occurs at 1:49 AM (March 20) on the east coast and 10:49 PM (March 19) on the west coast.

Bill Nye said, "Most days, the shadows of flagpoles, trees, and posts track graceful hyperbolic curves, here on Earth and on Mars. But on the day of an Equinox, they become straight lines. On the 19th and 20th, we'll all be able to watch those straight shadow paths on EarthDials around the world."

Updated images of each EarthDial are posted on The Planetary Society's website every 5-10 minutes. One gains a tangible sense of Earth's rotation by watching shadows travel across the face of each EarthDial and dissolve into darkness as that corner of the world rotates away from the Sun. At any given moment, EarthDials on half of the planet are in darkness.

EarthDials are located in the United States (Virginia, Maryland, New Jersey, Ohio, Wisconsin, California, and Washington state), Honduras, Malaysia, England, Spain and Antarctica, but this last one is now entering six months of darkness so is only barely visible. However, you can still see time-lapse movies of this and other stations on the website.

While the EarthDials are all made to a common pattern, each is decorated in the language and cultural motifs of its host. They are visually reminiscent of the MarsDials aboard NASA's Spirit and Opportunity rovers, which arrived on Mars in January 2004. Both the EarthDials and the MarsDials bear the common motto "Two Worlds One Sun," because the shadows on both worlds are cast by light from the same star, our Sun.

The EarthDial Project will run at least for the duration of the rovers' missions on the surface of Mars, which is expected to be 3-6 months. More EarthDials will be added in the coming months.

The team that developed the MarsDials for rovers Spirit and Opportunity included Nye and Sullivan as well as Steve Squyres, the principal investigator for the rover missions; Louis Friedman, Executive Director of The Planetary Society; James Bell, lead researcher for the high-resolution stereo panoramic cameras carried by both rovers; Tyler Nordgren, University of Redlands in California; and Jon Lomberg, artist and creative consultant to the Mauna Kea Center for Astronomy Education, University of Hawaii at Hilo.

Related Links
EarthDial
MarsDial at Planetary Society
SpaceDaily
Search SpaceDaily
Subscribe To SpaceDaily Express

Spring Begins On March 20th..
Or Is It The 19th?
Los Angeles - Mar 16, 2004
The coming of spring in 2004 will pose a bit of a quandary for weather announcers and others in the news media. Does it happen on March 19th or 20th?

The Year Of Living Occassionally
Sydney - Feb 29, 2004
Who? Well, Hilarius died on February 29th, 465. He was the 46th Pope, and did much to crush the insidious Eutychianism heresy which held that the human aspect of Christ's nature was subsumed by his divinity. Not many people are overly concerned about the heresy these days, but Saint Hilarius has a claim to fame which will stand for all time, writes Pat Sheil.



Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only














The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.