The eyes see only what the mind is prepared to comprehend.
Image of Mars is from the Hubble Space Telescope 5/June//2001
In the year 57,617 BCE Mars passed within 55 million kilometers of Earth (or 34 million miles) and, except for August 27, 2003, Mars will not be this close again until August 28, 2287. To celebrate the Department of Physics, in collaboration with the Center for Astrophysics at the University of Notre Dame, is pleased to present Mars Nights at Notre Dame at the Nieuwland Science Hall Observatory.
It has been some 60,000 years since an "opposition" like this has occurred with the Sun, Earth, and Mars. "Opposition" occurs when the Sun, Earth and Mars are lined up in their orbits with Earth directly between the Sun and Mars. Although this kind of alignment happens every two years, this event is highly unusual because the orbits of Earth and, especially, Mars are not perfect circles. Much detail can already be seen with telescopes having a diameter of at least 6 inches. Even now Mars will appear to the human eye as a very bright reddish object in the southern sky after 9:30 p.m.
Join us for Mars Nights at Notre Dame to see the Polar Ice Cap and the Syrtis Major Plateau on Mars on August 22nd and 23rd on the rooftop (or 5th floor) of the Nieuwland Science Hall Observatory between 9:30 p.m. and 11:30 p.m. Your next opportunity to see Mars this close will be in 284 years!
Important: Mars Nights at Notre Dame is weather dependent: if the sky is cloudy or overcast the Observatory will be closed.
Directions to the Nieuwland Observatory: Parking is only available in the visitor parking lot. Please see one of the following for a map of campus and the location: [pdf file] or [ps file].
Once on campus the best way to reach the Observatory is to take the steps at the Main Entrance of Nieuwland Science Hall Observatory (across from LaFortune Student Center) to the 4th floor. Walk straight down the hall (just past Room 410) and to the left is a door leading to another flight of steps on the left (signs will be posted). Lastly, follow the steps up, turning left, and stepping onto Nieuwland's rooftop.
Unfortunately, the Observatory is not handicapped accessible. However, arrangements can be made if anyone requires the need of an elevator and are then able to travel a flight of steps to the 5th floor.
If you need assistance or have any questions regarding Mars Nights at Notre Dame please contact event coordinator Suzanne Aleva at (574) 631-0926.
Opposition occurs when the Sun, Earth and Mars are lined up in their orbits with Mars being directly opposite to the Sun as seen from the Earth.
Because our solar system's planets do not revolve in perfect circles around the Sun, planets will be close to the Sun on one side of its orbit and further away on the other side. Perihelion is defined as the orbital point of closest approach to the Sun.
Aphelion is defined as the orbital point of greatest distance from the Sun.
| Sun | -27 |
| Moon | -13 |
| Venus | -5 to -2 |
| Jupiter | -3 to -1 |
| Mars | -2 to +2 |
| Mercury | -2 to +3 |
| Sirius (brightest star) | -1.4 |
| Vega | 0 |
| Saturn | 0 to +1 |
| stars in the Big Dipper | +1.8 to +3.3 |
| stars in the Little Dipper | +2.0 to +5.0 |
| Uranus | +6 |
| Neptune | +8 |
| Pluto | +14 |
| faintest ground-based telescope | +28 |
| Hubble Space Telescope limit | +30 |
The "magnitude" of a star is the term astronomers use to refer to the brightness of a star. The magnitude system was originally created by the Greek astronomer Hipparchus around 130 B.C.E.. He divided the stars he could see with the unaided eye into six classes. The brightest stars were grouped into the first class. The faintest stars were grouped into the sixth class. And the remaining stars were classified among other four classes accordingly. A bright star would be said to have a magnitude of 1 while a very dim star would have a magnitude of 6. It is crucial to notice that the smaller an object's magnitude, the brighter it is, and the larger the magnitude, the dimmer it is.
In the 19th century, with more accurate instruments than just the human eye, astronomers noticed that a difference of 5 Hipparchus magnitudes (e.g., our 1st and 6th magnitude stars) meant approximately a factor of 100 in brightness. So they defined this to be true and thus created the present magnitude system as a refinement of the old one. Under this new system, very bright stars or objects can have a magnitude of 0 (such as Vega) or even negative numbers! It also means that the difference of a single magnitude corresponds to a difference of about 2.5 in brightness. The table on the right shows the magnitudes of some well-known objects.
The brightness of an object also depends on its distance. There are then two different types of magnitudes: the "apparent magnitude" (how bright an object appears) and the "absolute magnitude" (how bright an object really is compared to other objects at the same distance). An intrinsically brighter star than another can be fainter if it is further from Earth. Conversly, dim stars can appear bright if they are very close to Earth and many of the night sky's brightest stars are so because those stars happen to lie nearer to Earth than the others.