Earth Changes
The circumhorizon arc looks like an upside down rainbow, but it's formed differently. Rainbows occur when light is refracted by water droplets, usually just after rain. Circumhorizon arcs however are one of many halos that can be formed by light's interaction with ice crystals.
Ice crystals are found high in the sky and can refract light into a variety of halos and shapes depending on where the sun is in the sky relative to the ice crystals and what kind of crystals are present. To form a circumhorizon arc the light is refracted by plate crystals oriented so that the light can enter through the plate's side.

Nearly 300 earthquakes have been recorded in just ten days near Spain’s Canary Islands raising fears of a volcanic eruption.
Almost 300 earthquakes have shaken the territory of the biggest islands of the Canary archipelago, Tenerife and Gran Canaria, over the last ten days. According to the Spanish National Geographic Institute, the biggest one, a 3.2 magnitude on the Richter scale, happened 35 km away from the Port of Las Palmas de Gran Canaria.
The area is the home to the world's third-tallest volcano, Mount Teide and the National Park of the same name, which is one of the most visited tourist destinations, with lots of volcanos.

Flooding in the north of Rock Creek in the Boundary region of the B.C. Interior.
Swollen rivers in B.C.'s Interior have spilled their banks, leaving valleys dotted with small lakes and changing what is normally the province's prime ranch country into otherworldly, mirrored paddy fields.
In some places, roads have been washed out and the ground under electricity poles has been so eroded that power lines have come down.
Police say the CBD has been hit hard, forcing the closure of many roads and with more heavy rain expected on Friday, motorists are urged to stay off city roads.
Streets turned into fast-flowing rivers, with water surging inside homes and businesses.
Comment: Hobart city recorded more than 100mm of rain in a single day for the first time ever in May - doubling the previous record.
"The snow on the ground is as thick as half a foot. This is our first snowfall experience of snowfall in April/May,"said locals.
The construction of Beni-Jomsom-Korala road under the national pride project has been obstructed due to the snow.
At least 11 people were killed and nine others injured by lightning strikes in eight districts across the country on Thursday.
In Habiganj, a farmer and a school girl were killed when a thunderbolt hit them at separate places in Baniachong upazila.
The deceased were identified as Tarin, 15, a sixth grader of Sujatpur High School, and Mizanur Rahman, a farmer. Both were residents of Sotomukha village in Sujatpur union.
Comment: A day earlier came this report: 29 killed in lightning strikes in 24 hours across Bangladesh - 112 such deaths in May so far
In Cambodia two people were also killed by lightning recently.

A blast of cold air from the Antarctic will hit Victoria on Thursday with a maxiumum temperature of just 13 degrees forecast for Melbourne.
According to the University of Georgia, a two-headed fawn was discovered near the town of Freeburg in 2016. Scientists with the Minnesota Department of Natural Resources, the University of Minnesota and the University of Georgia published a study on the animal last month. They say the conjoined twin fawns are the only ones known to have been carried to full term in the wild.
The mushroom hunter discovered the fawn about a mile from the Mississippi River and called the DNR right away. Experts say it looked like the mother had cleaned the two-headed doe, though testing on the animal's lungs confirmed it never breathed air — it was stillborn.
A calf born with two-heads on a ranch Antalya in Turkey's west shocked onlookers who had never encountered such a birth in over 10 years of animal rearing.
Thirty-eight-year-old farmer Fatma Öncel, a mother of three, was left scratching her head when she arrived on the farm in the morning to feed her cattle, and realized a cow had gone into labor.
Reports reaching the state headquarters claimed that four persons in Etawah and Agra, three in Mathura, two in and Ferozabad, one each Aligarh, Hathras and Kanpur Dehat were killed in separate incidents of house collapse/tree and electric pole felling and lightning.
Reports claimed that Western parts of Uttar Pradesh, particularly the Agra division, was worst-affected again when yet another 68 Km/hour high-velocity winds hit the state, third in less than two months. The met department had warned about the storm in advance.
Comment: For details of the earlier storm, see: Powerful 'freak' dust storms kill over 125 people in north India, highest death toll in decades - UPDATES












Comment: Last week a similar situation arose on the other side of the country: By the numbers: The record-setting flood in New Brunswick, Canada - due to snow melt