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3 BCE
Big Bang
The Big Bang Theory is the leading explanation about how the universe began. At its simplest, it talks about the universe as we know it starting with a small singularity, then inflating over the next 13.8 billion years to the cosmos that we know today. -
Thefirst known asteroid
Giuseppe Piazzi discovers Ceres. Piazzi discovered Ceres, the first known asteroid, on January 1, 1801, the first day of the 19th century. -
Solar spectrup
William Wolleston sees dark lines in solar spectrum. Wollaston passed sunlight through a prism and noticed that there were numerous dark bands and lines in the spectrum. -
Metorite Shower
Meteorite shower at l'Aigle convinces scientists that meteorites have an extraterrestrial origin. A careful investigation of the shower by Edouard Biot convinced most skeptics that meteorites really do fall from the sky. -
Coriolis effect
Gaspar de Coriolis discovers Coriolis effect. The Coriolis effect, the apparent deflection of moving bodies due to Earth's rotation, explained many atmospheric circulation patterns -
h Carinae
h Carinae brightens to become second brightest star. h Carinae is normally too faint to be seen, but between 1837 and 1860 it was the brightest star in the sky. -
The distance
Friedrich Bessel, Wilhelm Struve, Thomas Henderson measure the distances of stars. Bessel, Struve, and Henderson, working independently, almost simultaneously measured the parallaxes, and hence the distances, of nearby stars. These were the first measurements, rather than estimates, of stellar distances. -
Doppler effect
Christian Johann Doppler describes the Doppler effect. Doppler discovered that the wavelength and frequency of a wave change if the source of the wave moves toward or away from the observer -
The descovery of neptune
Calculations of Adams and Leverrier lead to discovery of Neptune. Adams and Leverrier independently calculated the location of the unknown planet, Neptune, that was required to explain discrepancies in the orbit of Uranus. -
Earth´s rotation
Jean Foucault uses pendulum to demonstrate Earth rotates. Foucault showed that the pendulum swung in the same plane but the Earth rotated under it, causing an apparent change in the direction of the pendulum's swing. -
James Clerk Maxwell discovers...
James Clerk Maxwell discovers velocity distribution function for a gas. Maxwell showed that the distribution of velocities of the atoms or molecules in a gas depends on temperature and the mass of the molecules. -
Stars
William Huggins identifies chemical elements in stars. Huggins studied the spectra of bright stars and found that the dark lines in their spectra matched the wavelengths of atoms measured in terrestrial laboratories. -
Mars
Asaph Hall discovers Phobos and Deimos. Remarkably, the prediction that Mars had two small satellites was made by Jonathan Swift 151 years before Hall's discovery. -
How old is the sun?
Lord Kelvin and Hermann von Helmholtz estimate the age of the Sun. Kelvin and Helmholtz independently calculated the length of time it would have taken for the Sun to have shrunk to its present size. This time, called the Kelvin-Helmholtz time, is about 20 million years. -
Canals
Giovanni Schiaparelli discovers "canals" of Mars. Schiaparelli reported thin, dark lines crisscrossing the surface of Mars. The discovery raised the possibility of intelligent life on Mars
