Tag Archives: Saturn

NASA Space Place – Doing Science with a Spacecraft’s Signal

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 October, 2012.

By David Doody

2013february2_spaceplaceMariner 2 to Venus, the first interplanetary flight, was launched August 27 fifty years ago. This was a time when scientists were first learning that Venus might not harbor jungles under its thick atmosphere after all. A Russian scientist had discovered that atmosphere during the rare Venus transit of 1761, because of the effects of sunlight from behind.

Mariner 2 proved interplanetary flight was possible, and our ability to take close-up images of other planets would be richly rewarding in scientific return. But it also meant we could use the spacecraft itself as a “light” source, planting it behind an object of our choosing and making direct measurements.

Mariner 4 did the first occultation experiment of this sort when it passed behind Mars as seen from Earth in July 1965. But, instead of visible light from the Sun, this occultation experiment used the spacecraft’s approximately 2-GHz radio signal.

The Mariner 4 experiment revealed Mars’ thin atmosphere. Since then, successful radio science occultation experiments have been conducted at every planet and many large moons. And another one is on schedule to investigate Pluto and its companion Charon, when the New Horizons spacecraft flies by in July 2015. Also, during that flyby, a different kind of radio science experiment will investigate the gravitational field.

The most recent radio science occultation experiment took place September 2, 2012, when the Cassini spacecraft carried its three transmitters behind Saturn. These three different frequencies are all kept precisely “in tune” with one another, based on a reference frequency sent from Earth. Compared to observations of the free space for calibration just before ingress to occultation, the experiment makes it possible to tease out a wide variety of components in Saturn’s ionosphere and atmosphere.

Occultation experiments comprise only one of many categories of radio science experiments. Others include tests of General Relativity, studying the solar corona, mapping gravity fields, determining mass, and more. They all rely on NASA’s Deep Space Network to capture the signals, which are then archived and studied.

Find out more about spacecraft science experiments in “Basics of Space Flight,” a website and book by this author, www2.jpl.nasa.gov/basics. Kids can learn all about NASA’s Deep Space Network by playing the “Uplink-Downlink” game at spaceplace.nasa.gov/dsn-game.

2013february2_mariner4posterart_full

Caption: In this poster art of Mariner 4, you can see the parabolic reflector atop the spacecraft bus. Like the reflector inside a flashlight, it sends a beam of electromagnetic energy in a particular direction. Credit: NASA/JPL/Corby Waste. Click to see full-size version.

About NASA Space Place

The goal of the NASA Space Place is “to inform, inspire, and involve children in the excitement of science, technology, and space exploration.” More information is available at their website: http://spaceplace.nasa.gov/

Bob Piekiel Hosts Observing Sessions At Baltimore Woods – 2013 Observing Schedule

I’m pleased to have obtained the official schedule for Bob Piekiel’s Baltimore Woods programs for the 2013 observing season and have added them to the CNYO Calendar. For those who have not had the pleasure of hearing one of his lectures, attending one of his observing sessions, or reading one of his many books on scope optics (or loading the CD containing the massive Celestron: The Early Years), Bob Piekiel is not only an excellent guide but likely the most knowledgeable equipment and operation guru in Central New York. I’ve (Damian) attended two of the Baltimore Woods sessions already and plan to be present for as many of the scheduled events below as possible.

Note:

The Baltimore Woods events calendar is updated monthly. As such, I’ve no direct links to the sessions below. Therefore, as the event date nears, see the official Calendar Page for more information and any updates on the event.

Also…

* Registration for these events are required. Low registration may cause programs to be canceled.
* $5 for members, $15/family; $8 for nonmembers, $25/family.
* To Register By Email: info@baltimorewoods.org
* To Register By Phone: (315) 673-1350

* Friday, February 8th (Backup – Saturday 9th), 7-9 p.m.

(Available link HERE) Another fabulous look at the bright winter skies and all the glories surrounding the constellation of Orion, the Hunter. The king of the planets, Jupiter, visible as well, as will the ice giant Uranus.

* March 15 (Friday) – 16 (Saturday), 7-9 p.m.

Comet Panstarrs should be visible in the west shortly after sunset. Its brightness is a guess at this time, but it could be quite a stunning sight. Jupiter will be visible, along with the winter skies and some of the brightest examples of nebulae and star clusters.

* April 5 (Friday) – 6 (Saturday), 7:30-9:30 p.m.

Comet Panstarrs will be visible in the northwest after sunset, right next to the Andromeda galaxy! While we can’t be certain of its brightness, it may be a stunning sight. Jupiter will be visible all evening, and Saturn will be rising in the east.

* May 4 (Saturday) – 5 (Sunday), 8-10 p.m.

Eta Aquariids meteor shower, Saturn and Jupiter visible all evening, and hello to spring skies.

* June 14 (Friday) – 15 (Saturday), 9-11 p.m.

Because it gets dark very late in June, it makes sense to do a 1st-quarter moon program, as we don’t need dark skies to get great views of the moon. Saturn will also be visible, and the start of summer skies.

* July 12 (Friday) – 13 (Saturday), 9-11 p.m.

The summer milky way at its finest. During the summer, we look directly into the core of our own milky way galaxy, giving great views of many beautiful star clusters and nebulae. The planet Saturn will be visible as well.

* August 12 (Monday) – 13 (Tuesday), 9-11 p.m.

It’s the annual Perseid Meteor Shower, one of the year’s finest, along with great views of the summer Milky Way, the ringed planet Saturn, and also Uranus and Neptune. Bring a lawn chair or blanket to lie back and watch for meteors when you’re not at a telescope.

* August 24 (Saturday) – 25 (Sunday), 1 p.m.

Solar observing session, with safe views of solar detail using specially-filtered telescopes.

* September 27 (Friday) – 28 (Saturday), 7-9 p.m.

Uranus will be in best viewing position all night long, plus Venus and Saturn in the west just after sunset. We will say goodbye to the Summer Skies.

* October 11 (Friday) – 12 (Saturday), 6:30-9 p.m.

Oct. 12 is National Astronomy Day, Part 2, but let’s do our usual Friday the 11th with Saturday being the backup. This will be our best chance to see Mercury for the remainder of the year, along with a crescent Moon and Venus as well, plus hello to Fall skies. We will need to start early to glimpse Mercury.

* November 4 (Monday) – 5 (Tuesday), 7-9 p.m.

Nov. 4-5 for the Taurid Meteor shower, plus hello to Winter skies. The Taurids are a modest shower, but in contrast, the Leonids, which occur on the 17th, are going to be completely washed out this year by a full Moon.

* December 13 (Friday) – 14 (Saturday), 7-9 p.m.

The Geminid Meteor Shower – the year’s best (it sure was fantastic last year!) and Winter skies, with the brightest examples of clusters and nebulae, such as the great Orion Nebulae.