Top 10 Sun factsSun quiz
What is larger in the sky: the Moon or the Sun? (By apparent size)
Sometimes the Moon, sometimes the Sun. The Moon's orbit is elliptical, and its apparent diameter varies by 10%. This is why both total eclipses (if the Moon is larger) and annular eclipses (if the Sun is larger) happen.
In which month is the Earth closest to the Sun?
In January. Earth's perihelion occurs around January 3, and the aphelion around July 4. The distance change is about 3.5%, which gives 6.9% increase in solar energy reaching the Earth at perihelion relative to aphelion. Since the southern hemisphere is tilted toward the perihelion, the southern hemisphere receives more energy from the Sun than does the northern over the course of a year.
The bright circle around the Sun seen in the picture is known as a halo. What causes it?
Refraction of light in ice crystals. Halo is the name for a family of optical phenomena produced by light interacting with ice crystals suspended in the atmosphere. Halos can have many forms, ranging from colored or white rings to arcs and spots in the sky. Among the best known halo types are the circular halo (properly called the 22° halo), Other common optical phenomena involving water droplets rather than ice crystals include the glory and the rainbow.
What is the temperature of the center of the Sun?
16 million degrees Celsius. The surface temperature is only 5500 degrees Celsius.
When is the Sun directly overhead (at the zenith) in Rome?
Never. Tropic of Cancer and Tropic of Capricorn mark the northernmost and southernmost latitudes at which the sun may be seen directly overhead. Since the whole Europe is north of the Tropic of Cancer, it is impossible to see the sun at the zenith there.
When was the photovoltaic cell invented?
1839. The first experimental photovoltaic cell has been built by Edmund Becquerel, French physicist aged 19 at the time, in his father garage in 1839. In 1883 Charles Fritts created the first solid state cell.
What properties do sunspots have?
Lower temperature and strong magnetic field. Sunspots are temporary phenomena on the Sun's photosphere that appear as spots darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic field flux that inhibit convection.