Sun-Earth Day Presents: Eclipse, In a Different Light
Sun Watchers Through Time:
3000 BC:
Known in Gaelic as Uaimh na Greine, "the cave of the sun," Newgrange , Ireland was built. It is the oldest known structure with evidence of scientific thought. On winter solstice, the sunlight perfectly aligns with an opening in the structure to illuminate the inner chamber.2700-1700 BC:
Stonehenge , in England , was built in approximately 3000 BC. It was a giant circle of huge stones that were aligned to the position of the sun.4th Century BC:
Greek philosopher Aristotle invented the camera obscura and became the first known person to use a device to observe the Simi. A camera obscura, a hole punched in a screen, remains a popular way to observe solar eclipses.150 AD:
Ptolemy endorsed the Earth-centered view of the universe.800 AD:
Chichin Itza was built by the Mayans in 800AD and was discovered in approximately 1566850 AD:
Chaco Canyon was a major center of ancestral puebloan culture between 850 and 1250.1543:
Nicolaus Copernicus published his theory that Earth travels around the sun. This contradicted the teachings of the Church.1608:
Dutch eyeglass maker Hans Lippershey invented the refracting telescope. Other scientists soon followed suit, making their own instruments.1609:
Johannes Kepler published his work, New Astronomy , in which he announced his three laws of planetary motion. His work described the orbits of the planets as elliptical, rather than circular.1610:
Galileo Galilei published his findings of his observations with his telescope. He described spots on the sun, craters on the moon and four satellites of Jupiter. His findings promoted the idea of a sun-centered universe (like Copernicus).1687:
Sir Issac Newton published his findings ( Principia Mathematica ) establishing the theory of gravitation and laws of motion. This allowed astronomers to understand the interacting forces among the sun, the planets and their moons.1814:
Joseph von Fraunhofer built the first accurate spectrometer and used it to study the spectrum of the sun's light.1843:
German amateur astronomer Heinrich Schwabe, who had studied the sun for 17 years, announced his discovery of a regular cycle in sunspot numbers. He discovered that the number and positions of sunspots vary over an 11-year period.1868:
During an eclipse, astronomers observed a new, bright emission line in the spectrum of the sun's atmosphere. As a result of observations, British astronomer Norman Lockyer identified and named helium.1908:
American astronomer George Ellery Hale showed that sunspots contain magnetic fields that are thousands of times stronger than Earth's magnetic field.1938:
German physicist Hans A. Bethe and American physicist Charles L. Critchfield demonstrated how a sequence of nuclear reactions, called the proton-proton chain, make the sun shine.1957:
Russian satellite Sputnik 1 was launched into orbit. Four months later, the US launched its first satellite, Explorer.1981:
NASA's first reusable space shuttle, Columbia , made its maiden flight.1983:
Launch of manned SpaceLab gave long term high-resolution photographs of the sun's surface.1990:
Ulysses, an interplanetary spacecraft, was launched with the mission to measure the solar wind and magnetic field over the sun's poles during periods of both high and low solar activity.1991:
Launch of the YOHKOH spacecraft, photographing the sun in x-ray emission over a full solar cycle (11 years).1995:
The Solar and Heliospheric Observatory (SOHO) is a joint project of the United States (NASA) and the European Space Agency (ESA). SOHO is at a point in space where the sun's gravitational pull balances Earth's gravitational pull, so the satellite orbits the sun with Earth. SOHO always faces the sun. SOHO returned some of the amazing images of the sun seen in SOLARMAX.1998:
Launch of the TRACE satellite, giving unprecedented close-up pictures of the sun and its magnetic field lines.1998:
Construction began on a huge new space station, a joint endeavor among many countries.2000:
YOHKOH, SOHO and TRACE images for SOLARMAX.
