Current Events

  • Irish Chronicles Document Links Between Volcanoes and Weather
    A study of over 40,000 written entries in Irish Annals and ice core measurements shows a strong corr...Read more

    x

    Irish Chronicles Document Links Between Volcanoes and Weather

    A study of over 40,000 written entries in Irish Annals and ice core measurements shows a strong correlation between the occurrence of volcanic eruptions and extreme cold weather in Ireland over a 1200 year period. Data analyzed in this study cover the period from 431 to 1649, during which time up to 48 volcanic eruptions are identified in Greenland ice core records through deposition of volcanic sulfate in annual layers of ice. You can find the study (open access), published on 6 June 2013 in IOP Publishing's journal Environmental Research Letters, at http://iopscience.iop.org/1748-9326/8/2/024035/article. Find out more about how volcanoes can influence climate.
  • EF-5 Tornado in El Reno, Oklahoma Widest Ever Recorded in US
    The EF-5 tornado that hit El Reno, Oklahoma on May 31st was the widest ever recorded in the US, acco...Read more

    x

    EF-5 Tornado in El Reno, Oklahoma Widest Ever Recorded in US

    The EF-5 tornado that hit El Reno, Oklahoma on May 31st was the widest ever recorded in the US, according to the National Weather Service in Norman Oklahoma. The tornado, which remained on the ground for 40 minutes and reached 2.6 miles across (4.2 km), took the lives of 18 people including storm chasers Tim Samaras, Paul Samaras and Carl Young. For more information on the tornado, visit http://ow.ly/i/2hfDG.
  • Atmospheric CO2 Level Tops 400 ppm
    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm rep...Read more

    x

    Atmospheric CO2 Level Tops 400 ppm

    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm repeatedly. Daily levels of CO2 can vary due to weather, and there are seasonal trends as well. The level of atmospheric greenhouse gases continues to increase, now over 120 ppm since the Industrial Revolution began. For more on the Keeling Curve, see http://keelingcurve.ucsd.edu/. Find out more about greenhouse gases and warming.
Saturn's one large moon, Titan, and several of the ringed planet's medium-sized moons. Earth's Moon is also shown for size comparison.
Click on image for full size
Original Windows to the Universe artwork by Randy Russell using images courtesy NASA.

Large and Medium-sized Moons of Saturn

Saturn has moons. Many of those are tiny chunks of rock or ice only a few kilometers (miles) across. One of Saturn's moons, Titan, is much larger than the rest and is amongst the largest moons in our entire Solar System.

Midway in size between Titan and the many tiny moonlets are several medium-sized moons. The image on this page shows Titan and the mid-sized moons of Saturn. They are, in order from largest to smallest: Rhea, Iapetus, Dione, Tethys, Enceladus, Mimas and Hyperion. Two more moons, Phoebe and Janus, are visible in the larger version of this image (click on the small image on this page to see the larger image). The picture also shows Earth's Moon for size comparison.

Last modified June 7, 2004 by Randy Russell.

Shop Windows to the Universe Science Store!

Our online store includes fun classroom activities for you and your students. Issues of NESTA's quarterly journal, The Earth Scientist are also full of classroom activities on different topics in Earth and space science!

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Titan

Titan is the largest moon of the planet Saturn. Titan is the second largest moon in our Solar System. The diameter of Titan is 5,150 km (3,200 miles), which is about the distance across the United States....more

A Comparison of Some Major Moons, and the Earth's Moon

This is an image of the Earth's moon, shown in the center, with several other moons for comparison. The image shows that the Earth's moon is a lot smaller than Ganymede, Callisto, and Titan. The Earth's...more

Rhea

Rhea was discovered by G. Cassini in 1672. Rhea is the 5th farthest moon from Saturn. It is one of the icy moons, similar to the Galilean satellites. Rhea is about as wide as the state of California is...more

Dione

Dione was discovered by G. Cassini in 1684. Dione is the 7th farthest moon from Saturn, with a standoff distance of 377,400 km. It is a small icy moon, lightly cratered, with wispy white streaks across...more

Tethys

Tethys was discovered by G. Cassini in 1684. Tethys is the 8th closest moon to Saturn, with a standoff distance of 294,660 km. It is one of the icy moons, similar to the Galilean satellites. Tethys is...more

Enceladus

Enceladus is a moon of Saturn. It is Saturn's sixth largest moon. Saturn has // Call the moon count function defined in the document head print_moon_count('saturn'); moons. Enceladus was discovered in...more

Hyperion

Hyperion was discovered by W. Bond in 1848. Hyperion is the 3rd farthest moon from Saturn, with a standoff distance of 1,481,000 km. Hyperion is 175 x 100 km (117 x 67 miles) in size. Its dimensions make...more

Saturn's Moons and Rings

The gas giant planet Saturn has a large group of // Call the moon count function defined in the document head print_moon_count('saturn'); moons. It also has the largest, most complex, and best-known ring...more

Shop Windows to the Universe

The Winter 2010 issue of The Earth Scientist includes a variety of educational resources, ranging from astronomy to glaciers. Check out the other publications and classroom materials in our online store.

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF