Spring gets its official start Friday in the Northern Hemisphere with the arrival of the vernal equinox. But what does that mean? The Earth's axis is tilted at an angle as it travels around the sun. On the equinox, the Earth's tilt is neither toward nor away from the sun, so both hemispheres get the same amount of sunlight. This means day and night last about the same amount of time. It also marks the start of a new season. Days will get a little longer every day in the Northern Hemisphere until the solstice in June.
El Nino warps weather worldwide. Meteorologists say the natural El Nino cycle is both adding to and feeling the heat of a warming world. A new study says a shift from a rare three‑year La Nina to a strong El Nino recently helped trap extra heat in the climate system. Study authors say between warming from greenhouse gases and that La Nina to El Nino change, it explains three-quarters of Earth's energy imbalance, which leads to extra heat. Warmer waters are also causing NOAA to shift how it calculates and labels this cycle, which likely means more La Ninas and fewer El Ninos.
Sunday marks the shortest day of the year in the Northern Hemisphere, signaling the start of astronomical winter. In the Southern Hemisphere, it's the longest day, marking the beginning of summer. The term "solstice" comes from Latin, meaning the sun's "pause" in its annual path. After the winter solstice, the sun begins to climb higher, and days gradually lengthen until late June. Solstices have been celebrated for ages, with monuments like Stonehenge aligning with the sun's paths. The equinox, in contrast, is when both hemispheres receive equal sunlight, leading to nearly equal day and night lengths.
A new study finds that climate change is already causing all sorts of problems on Earth, but soon it will be making a mess in orbit around the planet too. MIT researchers calculate that as global warming continues it may reduce the available space for satellites in low Earth orbit by anywhere from one-third to 82% by the end of the century. That's because climate change makes the upper atmosphere cooler and less dense. Dead satellites and debris won't fall to Earth as much, which is nature's way of cleaning up what humanity launches. So space will become more littered.
The latest solar storm has triggered northern lights farther south than normal including into parts of Germany, the United Kingdom, New England and New York City. There were no immediate reports of disruptions to power and communications from Thursday's storm. Friday forecast shows continued higher-than-normal activity, but the chances for another overnight show are slim farther south of Canada and the northern Plains states. The sun is near the peak of its current 11-year cycle, sparking all the recent solar activity. In May, Earth got slammed by severe solar storms, the strongest in more than two decades.
