GeekwithEnvy

Weather

Saturn’s Great Hurricane

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nasaSaturnRose
“The Rose” in False-Color Image Credit: NASA/JPL-Caltech/SSI

We haven’t really had the opportunity to see Saturn’s north pole, at least with any great clarity, since the last time we got close which was in 1981 when Voyager 2 was making it’s way past our solar system’s second largest planet. Thankfully, Cassini on Nov. 27, 2012 has offered up an updated and much more detailed view of the northern pole of Saturn and what they found was spectacular.

A massive vortex was discovered that spans 1,250 miles (2,000 kilometers) across with clouds whizzing around at 330 miles per hour. It’s like a massive hurricane, one that’s many times as large and powerful as any hurricane on Earth. What’s also interesting about “the Rose” is that we are not sure how long it has actually existed. We will have to keep an eye on this storm and see how things progress throughout the year.

For more details about Cassini and associated projects along with more amazing photos, you can head the NASA’s Cassini page.

A Quick Look at How Lightning Works and a Cool Video

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It’s that time of year again in most the United States when we start to see warming temperatures and that means a lots of thunderstorms. We see the flash and then hear the rumble of thunder as we witness the power of our planet’s weather system.

Although many of us have experienced a thunderstorm, few truly understand what’s going on out there when lightning strikes. It’s quite clear why it would be difficult to determine exactly what’s going on when a thunderstorm produces lightning, after all, lightning happens in a split second. Thankfully, there are lots of people out there studying storms and using high speed cameras to slow everything down, this helps us get a clearer picture of what’s happening. One of those people is Tom A. Warner, a photographer who has captured some amazing footage of lightning, among many other things.

Lightning occurs when a storm becomes electrified. As the storm moves over an area, it’s negative charge causes the ground around it go become positively charged. This build up and difference in electrical charge is why lightning occurs. What’s even more interesting is that the lighting doesn’t just come lying out of the cloud, at least not initially. A Stepped Leader (-) begins to make it’s way down from the cloud as streamers (+) move upward from the ground. When the streamer meets the step leader then connection is complete and we see the resulting discharge as lightning. In the video above you can clearly see the Stepped Leader searching for the best path for the lightning to take.

Anything can produce a streamer towards a storm cloud, it’s usually a tall object but even you could be producing one. What’s worse is you could become part of the circuit and bam, you’ve been hit by lightning. That’s why it’s important to follow safety guidelines if your caught in a storm

Lightning Animation B
Stepped Leader Animation (Credit: NOAA)
Lightning Animation A
Streamer Animation (Credit: NOAA)

 

 

 

Catch The Lyrid Meteor Shower This Weekend

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lyridsFromSpace
The Lyrid Meteor Shower as seen from the International Space Station (Source:NASA)

Every year the Earth passes through an area of debris in space that is left behind from Comet Thatcher. When we pass through this area of dust, we on the Earth’s surface get to see quite a show.

This meteor shower is known as the Lyrid meteor shower and the radiant of the shower (where the shower appears to originate) is near the brightest star in the constellation Lyra, Vega. The shower will be at it’s peek this weekend on April 21 and 22 (Sunday night and early Monday morning).

Unfortunately, many of us will have difficulty observing this event as the Moon will be very bright, almost full. No need to get discouraged though as you should still be able to see many of them anyway, especially farther away from sources of light pollution like bigger cities. As you watch space debris streak across the sky, think about how they are moving at over 100,000 mph or 160,934 km/h, it’s pretty cool stuff.

A Quick Guide to Understanding the Equinox

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NorthHemiSeasons

The Earth is tilted in relation to the sun. Earth’s axial tilt to orbit is 23.44°. On March 20th 2013, this marked the Spring Equinox for the northern hemisphere. The Fall Equinox is in September and vice versa for the southern hemisphere. The Equinox is the point at which the Earth is neither leaning towards or away from the sun. The sunlight that hits the Earth is evenly distributed across the northern hemisphere and the southern hemisphere. From space, the terminator (where night meets day on the Earth’s surface) appears to be perfectly straight from north to south.

After the equinox, the sunlight begins to either become more direct or less direct depending on which hemisphere you live in. The Solstice is the point at which the sun appears at either it’s highest or lowest point in the sky or when the Earth is tilted all the way towards or away from the sun. These are known as the summer and winter solstices.

Interestingly, the orientation of the Earth’s axis actually changes very slowly before making a complete circle every 25,800 years.

The illustration above shows how the tilt of the Earth and it’s location in orbit around the sun, change how light falls on the Earth’s surface. For a really cool view of the Earth undergoing seasonal changes in sunlight, you can view this NASA animation made from images from a geosynchronous satellite above Earth.

King Tides Show Up On West Coast

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Tidal movements on Earth

For the next few days ocean tides will be much higher ( and lower) than they typically are due to a phenomenon called “King Tide”‘. These tides are popular among surfers as they create the best conditions for the sport. Some people use the very low tides to explore areas of the beach that are normally always underwater, a metal detector could turn up something cool.

So where do these King Tides come from? Well how these tides work is actually pretty amazing. Our orbit around the Sun isn’t a perfect circle, it’s actually an elliptical orbit. As the Moon travels around Earth it also travels in an elliptical orbit. This means that at certain points in our orbit around the sun or our moon’s orbit around the Earth, we are closer and farther away. When we are closest to the sun we call this point, the perihelion. When the moon is closest to Earth we call that point the perigee. When we are closer to the moon or the sun this causes us to see a greater influence from these celestial bodies on our tides.

Every once and a while the sun will be at perihelion and the moon will be at perigee at the same time, or very close to the same time. This causes the greatest posible influence on our tides (King Tide). We are closest to the sun in January and usually within the first week, we are farthest from our sun in July.