Yes, Texas has done Daylight Saving Time every year since 1918.
No. Mercury is essentially geologically dead and has been for billions of years.
The red spot on Jupiter, known as the Great Red Spot, has been observed for over 400 years. It was first documented in 1665 by Italian astronomer Giovanni Cassini.
Mercury has been observed for thousands of years, as early as the time of the Babylonians, who mentioned it in writing some 3000 years ago. The exact person who first discovered the planet has been lost to time, and is therefore indeterminate.
Saturn was discovered about 400 years ago.
Birtish scientist, Robert hooke discoverd first non-living cell in 1665. After some years a dutch naturalist Antonie van Leeuwenhoek discoverd first living cell. Antonie observed tiny small organisms from pond water under his microscope and called them as "animalcules". His word came to us as "cell".
Cholera is a disease... The disease cholera is caused by a bacterium. The bacterium was first described by Filippo Pacini in 1854, but it was Robert Koch's famous description thirty years later that was finally recognized.
On May 30, 1868, three years after the end of the US Civil War.
Auroras are a natural occurence and have been around for longer than humans have. This question is kind of like asking "When was the first snowfall observed?"...there is no "first observation".
The famously first-observed black hole in Cygnus known as Cygnus X-1 is about 6,070 light years distant.
Jupiter
President Ronald Reagan signed the holiday into law in 1983, and it was first observed three years later.
Every 4 years
Recalling endosymbiont-theory, many millions of years ago a cell was hungry and incorporated a bacterium. So the cell wrapped a lysosome around the bacterium and tried to digest it. But somehow the bacterium resisted and both found that it's an advantage for them to live in symbiosis. The cell fed the bacterium with nutrients and it reciprocated by donating his host energy (ATP). The proof lies within the form of the double membrane: the inner membrane has many wrinkles and resembles a bacterium while the outer membrane is smooth, like the mantle of a lysosome.
E coli is dead. she died 15 years ago
Mercury has been observed for thousands of years, as early as the time of the Babylonians, who mentioned it in writing some 3000 years ago. The exact person who first discovered the planet has been lost to time, and is therefore indeterminate.
It's not the same as a supernova--the Crab Nebula is the visible remnant of a supernova event which occurred about 7,500 years ago. The light from the supernova explosion reached the earth and was observed by Chinese and Arab astronomers about 1,000 years ago. The Crab Nebula was the first object to be identified with a supernova which was actually observed during recorded history.