This weekend we will attend a beautiful conjunction of Saturn with the waning quarter of the Moon. On Wednesday the 14th the conjunction will take place between Jupiter and a fine lunar edge. For a good observation of these conjunctions, it is necessary to look at the sky towards the east one or two hours before the Sun rises.
date with saturn
Early risers (and night owls) looking at the sky before sunrise will be lucky enough to catch a glimpse of two giant planets.. To do this, it is convenient to look to the southeast one or two hours before solar rising, that is, around 5 or 6 in the morning (peninsular time).
Jupiter is low above the horizon, but this giant planet is so extremely bright that it can already be seen without difficulty.. Of course, it is preferable to choose an observation point with a clear horizon, without trees or buildings, and at altitude if possible.
Further to the right is Saturn, which shines much more discreetly.. To be precise, the ringed giant is 16 times less bright than Jupiter.. And it is that, if it is 846 million kilometers from Earth, Saturn is 1.7 times further: 1,431 million kilometers away.
Complete the scene Fomalhaut, the brightest star in the constellation of the Austral Fish and one of the brightest in the night sky. Located 25 light years from Earth, it has an intrinsic luminosity 18 times more intense than that of the Sun.
Saturn rises these days around 2 in the morning, and Jupiter appears two hours later. From those moments, it is possible to see the calm ascent of the two giant planets until the colors of the dawn end up hiding their brilliance.. If we observe them on successive days, we will see that they both get up a few minutes earlier each day and, therefore, if we look at them one night after another at the same time, we will see that they are gaining in height with each passing day.
This weekend, Saturn will not rise alone, but will be accompanied by the Moon, which is now in its waning quarter; the full moon took place on the 4th and the new moon will take place on the 18th. At dawn on Saturday the 10th, both stars are less than five degrees apart, this is equivalent to the length of the thumb when the arm is extended.
With a small telescope, it is also possible to observe these nights (preferably those with less lunar illumination) the fascinating rings of Saturn. At this time, its inclination with respect to the line of gaze is small, making the perspective on the planet particularly stimulating.
rendezvous with jupiter
On the 14th, the action will have moved to Jupiter, since the Moon, already turned into a very fine illuminated edge, will be very close to the king of the planets. The separation of Jupiter from the illuminated limb of the Moon will then be a little more than one degree, that is, a little more than twice the apparent lunar diameter.
Jupiter conjunction with the Moon on the 14th
If you are lucky enough to be able to observe the scene through a small telescope, you will be able to get a beautiful view of the giant planet accompanied by its four largest satellites: Ganymede, Io, Europa and Callisto.. When Galileo discovered these moons in the early s. XVII, found that Jupiter behaved with them as a mini solar system, that not all bodies orbited the Earth, and this provided a major argument in favor of the heliocentric theory that changed the conception of the universe.
With the telescope it is also possible to see amazing details of the lunar relief in the area of the terminator (where the transition from the illuminated area to the one in the shadow occurs). And, with or without a telescope, it is always very interesting to observe the dark part of the lunar disk with its delicate ashen glow: it is the reflection of a reflection, it comes from sunlight that is first reflected by the Earth before reaching the Moon.
short nights
This year the summer solstice will take place on June 21, as we get closer to that date the nights are shorter and shorter. In our latitudes, we still have about five hours of total darkness to look at the starry sky in optimal conditions. But in more northerly latitudes, the Sun does not go very deep at night, and twilight lights complicate observations for more northerly astronomers.
However, in those northern latitudes (above 50 degrees), they are lucky enough to enjoy the wonderful noctilucent clouds that are produced in the highest layers of the atmosphere at the end of twilight, when the Sun shines from below the horizon.. The spectacles of nature, and particularly those that take place in the sky, always fascinate us, reminding us that we are part of a wonderful and vast cosmos.
Rafael Bachiller is director of the National Astronomical Observatory (National Geographic Institute) and academic of the Royal Academy of Doctors of Spain.