May 18th, 2012
03:46 PM ET

Get ready for the eclipse!

Folks in the western U.S. are gearing up for the a full annular solar eclipse this Sunday evening, May 20.

The eclipse will first begin over China as the Moon begins to pass between the Sun and the Earth, and it will first become visible to the West Coast of the U.S. at 5:12 pm PDT, Sunday evening.

Annularity, or the time when the Moon obscures the Sun the most, will begin at 6:23 pm PDT for the coasts of northern California. That spectacular view will only last a few minutes, and residents of West Texas will be the last to view the annular eclipse as the Sun drops below the horizon.

The last time a full annular solar eclipse was visible to the U.S. was May 10, 1994.

The next annular eclipse visible to the U.S. will not happen again until October 14, 2023, so if you have a view, you don’t want to miss this one!

Planning to view the eclipse? Share your photos with CNN iReport and they could be featured on CNN.

This week's Texas storm towered 8 miles high
An image from the TRMM weather satellite shows just how incredibly high this week's storms climbed over the region.
April 6th, 2012
03:15 PM ET

This week's Texas storm towered 8 miles high

Once again, NASA offers us a brilliant perspective of Mother Nature’s fury!

The animation above shows us a 3-D view from NASA’s Tropical Rainfall Measuring Mission (TRMM) Satellite of the storms that hammered the Dallas area and eastern Texas.

Rainfall rates reached up to 2 inches per hour at times during the strongest storms, while those storms also spawned several tornadoes across the region. Some of these twisters were powerful enough to pick up entire big rig trucks.

The stronger the storms are, the taller they are. In an average shower or weak thunderstorm, cloud tops can reach around 30, 000 feet high. When they're more intense, severe cousins develop like those across eastern Texas. Those cloud tops can reach to heights of 50,000 to 60,000 feet, or about 10 miles high!

Tuesday’s storms towered over eastern Texas higher than about 8 miles, or around 42,000 feet. Even the storms that were developing across eastern Louisiana and southern Mississippi reached to heights of around 7 miles.

While we know several of these storms were tornadic as they passed across eastern Texas, these images cannot indicate whether storms are severe, and certainly not if they are producing tornadoes. We still need the traditional radar to see if a storm is rotating or to determine if it is severe. But what we can do is see the intensity of the precipitation underneath those storms and estimate the height of the cloud tops.

This TRMM satellite is part of a joint mission between NASA and the Japanese Space Agency, JAXA. It orbits the globe about 16 times a day - about every 90 minutes. There are three instruments on this satellite, and the most innovative of those allows us to see these storms from a 3-D perspective. It's called the precipitation radar.

This instrument is what gives us a vertical profile of precipitation from the surface to a height of about 12 miles. It can detect precipitation as light as 0.7 millimeters per hour and can also detect frozen precipitation as the satellite orbits the Earth at about 250 miles above the surface.

TRMM is not just for looking at thunderstorms over land, but it's also a great tool for viewing tropical systems above open oceans.

Researchers do use other satellites to study tropical systems, but TRMM can provide a 3-D view of these storms and offer detailed information on the intensity and structure of precipitation in and around the eyewall, as well as the outer rainbands.

October 26th, 2011
11:29 AM ET

Spectacular aurora borealis

If you’ve ever seen the aurora borealis, you know what a spectacular sight it can be. You also know it’s all about location, location, location. The northern lights are generally only visible in the more northern latitudes, but this week, many people were seeing these amazing displays as far south as Georgia and Alabama. Why was this aurora event visible to so many?

The chain of events that caused the lights started as early as 9:36 p.m. on Friday, with the occurrence of a Coronal Mass Ejection. These CMEs are large eruptions of positively charged ions and negatively charged electrons from the sun that travel through space, sometimes heading toward the Earth. They can occur at any time, but typically, these events are more common during periods of high solar activity. From now until 2013, there will be a solar maximum, or a peak in solar activity, meaning we will likely see more events like these CMEs, as well as sunspots and solar flares.


  • Elizabeth Landau
  • Sophia Dengo
    Senior Designer