Daylight Astronomy

how to learn stargazing

Astronomy is a hobby that is not practiced only at night. Here are 10 celestial objects that you can see even in daylight.

Before starting, watch out for the sun !

Caution ! The observation of celestial objects presented here can be very dangerous for the eye. It is therefore necessary to be extremely cautious, especially if you are using an optical instrument such as a telescope, as sunlight passing through the lens can cause irreversible damage to your eye.

The Moon

moon

As you have certainly noticed, it is possible to see the Moon in broad daylight. You probably wondered how this was possible. As the Moon reflects much of the sun’s light, it can be seen during the day when our star is low on the horizon. Take advantage of these opportunities to see lunar phases that you would not have seen otherwise.

Venus

venus exploration

The planet Venus is often visible at dusk or shortly before dawn. Depending on its orbital position, it will appear either as a partially illuminated globe or as a crescent. It is so bright that you can sometimes see it in broad daylight if you know where to look. Be careful because it can be close enough to the Sun. Find out about the position of Venus before looking for it.

Jupiter

planet jupiter

The planet Jupiter is bright enough to be visible at the end of the day or at dawn. It is one of the first celestial objects to appear at dusk and disappear at dawn. It shines with a slightly yellowish shine. Through a telescope, you can admire the ballet of the galilean moons. For a daytime observation of Jupiter, use a computerized telescope (GoTo).

Comets

comet

Most comets that cross the sky can only be seen with a telescope. However, some of them may be bright enough to be seen with the naked eye or astronomy binoculars at dusk, in case they have survived their passage near the Sun.

Satellites

flash iridium

The Iridium satellite system is a network of telecommunications satellites orbiting the Earth. The particular shape of their reflective antennas reflects, for a few minutes, the light of the Sun on a small surface of the Earth. This luminous phenomenon, among the brightest in the sky, is called “Iridium flash”.

The sun

the sun

Before observing the Sun, make sure that you have placed on your telescope a light attenuator filter designed for this purpose. You will be able to safely observe solar stains and the solar granulation. If you do not have a filter, you can project the Sun’s image onto a piece of cardboard using a small telescope. But be careful !

Mars

planet mars

The planet Mars is much more difficult to see than Venus because it is less brilliant. It can, however, be seen at dusk just after sunset or shortly before dawn. You can observe it in broad daylight using a GoTo telescope or an equatorial telescope with graduated rings and an ephemeris, or a star map showing you its position.

Stars

nightsky trees

Several stars can be observed at dusk. However, it is possible to see the brightest of them shortly before sunrise. For this, you will need a telescope. Sirius is one of those stars that can be seen in the winter in the morning, down on the horizon towards the south.

The ISS

the international space station

The International Space Station turns several times a day around the Earth. Depending on its orbital position, you can see it cross the sky from west to east. Its solar panels reflect the light so intensely that they are visible at dusk.

Atmospheric phenomena

parhelion

The interaction of sunlight with the atmosphere can produce amazing optical phenomena such as parhelions. In a hazy sky, they can look like a small rainbow on either side of the Sun. This is caused by high-altitude ice crystals that refract sunlight. The crepuscular rays are rays of the sun passing through the clouds. They are parallel rays emerging from the sun hidden by the clouds.



Images credits

  • Sun : NASA [Public domain]
  • Moon : NASA [Public domain]
  • Venus : Image processing by R. Nunes http://www.astrosurf.com/nunes [Public domain]
  • Jupiter : NASA/JPL/USGS [Public domain]
  • Comet : ESA/Hubble [CC BY 4.0 (https://creativecommons.org/licenses/by/4.0)]
  • Flash Iridium : Andrew Echols [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/)]
  • Mars : ESA – European Space Agency & Max-Planck Institute for Solar System Research for OSIRIS Team ESA/MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA [CC BY-SA 3.0-igo (https://creativecommons.org/licenses/by-sa/3.0-igo)]