Tag Archives: Carl Sagan

NASA Space Place – Twenty Years Ago on Mars…

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in July, 2017.

By Linda Hermans-Killiam

2013february2_spaceplaceOn July 4, 1997, NASA’s Mars Pathfinder landed on the surface of Mars. It landed in an ancient flood plain that is now dry and covered with rocks. Pathfinder’s mission was to study the Martian climate, atmosphere and geology. At the same time, the mission was also testing lots of new technologies.

For example, the Pathfinder mission tried a brand-new way of landing on Mars. After speeding into the Martian atmosphere, Pathfinder used a parachute to slow down and drift toward the surface of the Red Planet. Before landing, Pathfinder inflated huge airbags around itself. The spacecraft released its parachute and dropped to the ground, bouncing on its airbags about 15 times. After Pathfinder came to a stop, the airbags deflated.

Before Pathfinder, spacecraft had to use lots of fuel to slow down for a safe landing on another planet. Pathfinder’s airbags allowed engineers to use and store less fuel for the landing. This made the mission less expensive. After seeing the successful Pathfinder landing, future missions used this airbag technique, too!

Pathfinder had two parts: a lander that stayed in one place, and a wheeled rover that could move around. The Pathfinder lander had special instruments to study Martian weather. These instruments measured air temperature, pressure and winds. The measurements helped us better understand the climate of Mars.

The lander also had a camera for taking images of the Martian landscape. The lander sent back more than 16,000 pictures of Mars. Its last signal was sent to Earth on Sept. 27, 1997. The Pathfinder lander was renamed the Carl Sagan Memorial Station. Carl Sagan was a well-known astronomer and science educator.

Pathfinder also carried the very first rover to Mars. This remotely-controlled rover was about the size of a microwave oven and was called Sojourner. It was named to honor Sojourner Truth, who fought for African-American and women’s rights. Two days after Pathfinder landed, Sojourner rolled onto the surface of Mars. Sojourner gathered data on Martian rocks and soil. The rover also carried cameras. In the three months that Sojourner operated on Mars, the rover took more than 550 photos!

Pathfinder helped us learn how to better design missions to Mars. It gave us valuable new information on the Martian climate and surface. Together, these things helped lay the groundwork for future missions to Mars.

Learn more about the Sojourner rover at the NASA Space Place: https://spaceplace.nasa.gov/mars-sojourner

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Caption: The Mars Pathfinder lander took this photo of its small rover, called Sojourner. Here, Sojourner is investigating a rock on Mars. Image credit: NASA/JPL-Caltech

About NASA Space Place

With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov (facebook|twitter) to explore space and Earth science!

Asteroid 2012 DA14 (& Little Hope For CNY (Viewing))

Greetings fellow astrophiles!

I begin with a little bit of history from the NASA Voyager website: voyager.jpl.nasa.gov

The Voyager delivery accuracy at Neptune of 100 km (62 mi), divided by the trip distance or arc length traveled of 7,128,603,456 km (4,429,508,700 mi), is equivalent to the feat of sinking a 3630 km (2260 mi) golf putt, assuming that the golfer can make a few illegal fine adjustments while the ball is rolling across this incredibly long green.

I include this piece of historical content to put into context any discussion about a 2012 DA14 impact (which, at this point, falls clearly into the conspiracy theory regime). The world has a very good handle on Newtonian Mechanics and, when it is reported by NASA physicists that something is going to miss the planet by 27,000 km (OK, fine. 27,000 km from the Earth’s center. As the point on the Earth’s surface farthest from the Earth’s center is 6,384 km away, DA14 will miss by “only” 20,616 km), you can believe it. If we can be off by 100 km after 12 YEARS in space, be assured we can be within that same 100 km with a year’s worth of data collection.

With the good news out of the way…

As the newest reports about 2012 DA14’s path make clear, its passing within geosynchronous orbit will be a treat for observers in Indonesia and an otherwise great view for Europe, Asia, and Africa. And by great, I mean that the predicted apparent magnitude will not reach smaller than 7.4 (smaller = brighter. Naked Eye viewing trails off rapidly after magnitude 4, making 2012 DA14 a “big binocular” object even at its closest approach. The Sun, on the other hand, is at magnitude –26.74 from Earth), so it will be great with the aid of optics. CNY, and the Americas in general, will only be able to observe 2012 DA14 on its “way out,” after closest approach. As it will be moving at quite a clip away from us, it will be quite a difficult object in CNY to find for anyone outside on the night of the 15th. Reports seems to indicate it will be at magnitude 11 by the time the East Coast could see it, which is a heroic magnitude for most any amateur telescope).

2012february8_2012DA14_path_v2

CAPTION: Path of 2012 DA14 (in Universal Time (UT) and as viewed from the Earth’s Center) on February 15/16. Click for a full-sized version. From www.virtualtelescope.eu.

And, if you’re still freaked out about impact, note that we (CNY) will STILL be on the wrong piece of Terran real estate. That said, its trajectory is even wrong for colliding with geosynchronous satellites, so your cell phone service won’t be impacted, either.

I am pleased to report that the best 4 minute discussion of 2012 DA14 has been put together by an organization I’ve been a member of for over 15 years – The Planetary Society (co-founded by Carl Sagan, currently CEO’ed over by Bill Nye, the list of activities in space science and public outreach is considerable). Bruce Bett’s youtube video is provided below. If Snow Storm Nemo has anything to say about it, you’ll have plenty of time this weekend to watch and take notes.

CAPTION: Planetary Society Director of Projects Bruce Betts reassures us in this brief and fascinating explanation of what will happen–and what WON’T happen–when this big asteroid comes closer to Earth than many satellites.

You can read a full article about 2012 DA14 at the Planetary Society website: www.planetary.org/explore/projects/neo-grants/2012da14.html. A thorough FAQ can be found at www.planetary.org/explore/projects/neo-grants/2012-da14-faq.html.