TRG – Telescope Review Guide

What can you see this month? A lot! So get out your best telescope or best binoculars and get to viewing!

May Sky on YouTube

Jupiter becomes more easily visible this month as its elevation in the pre-dawn sky is getting higher – about 23 degrees above the horizon by month’s end.   During May its separation from the Sun increases from 77 degrees to 101 degrees, and its magnitude slowly increases from -2.3 to -2.5.   It will lie just below the the last quarter Moon on the 17th in the pre-dawn sky.

Mars still remains low in the pre-dawn sky this month, but as it rises increasingly earlier than the Sun as the month progresses will become easier to spot.   It has a magnitude of +1.2.   By the end of the month, the angular separation from the Sun has increased to 40 degrees. We will have to wait a month or so until it will be seen easily in the pre-dawn sky.

Venus passed betwen the Earth and Sun in March so is now visible in the pre-dawn sky.   It will only lie 12 degrees above the horizon as the Sun rises on the first of May, so will be easier to spot later in the month.   It is at magnitude -4.4 at mid month, up and to the right of Mars.   In the middle of May, a small telescope will show a crescent phase equivalent to just before a first quarter Moon.   An interesting fact about its brightness is that it stays pretty constant at about -4.4 for most of the time that it is visible even though the apparent phase changes greatly.   When the phase is thin, Venus is nearer to us and the effective reflecting area of Venus as seen from Earth remains pretty constant.

Saturn is now high in the southern sky after nightfall in the constellation of Leo.  It lies well below the body of Leo.   It starts the month at magnitude +0.8 with an angular size of ~18.8 arc seconds and these fall to +0.9 and 18.1 as the month progresses.  Saturn is significantly less bright this year than it sometimes is: the rings are very close to edge on (as shown in the Hubble image of Saturn) and thus there is less apparent reflecting area.   During May they are at an angle of ~4 degrees from the line of sight.   The rings will be seen (or rather – not seen) edge-on later this year and it will not be until 2016 that they will be at their widest again.  A small telescope will easily show its largest moon, Titan, and show some bands around the surface.

What is in the night sky during April? The Moon, planets and even a meteor shower are on tap this month.
The Moon is especially noteworthy this month. It passes near all five of the naked-eye planets — Mercury, Venus, Mars, Jupiter, and Saturn plus as well as the stars Regulus and Antares. On the 22nd it will eclipse Venus as seen from most of the continental United States. 

Regulus, the brightest star of Leo, stands a little to the left or upper left of the Moon at nightfall on the 5th. The planet Saturn is below them.

Saturn aligns quite close to the Moon on the evening of the 6th, with Regulus above them.

Moon and Saturn by spaceritual

Antares, the brightest star of Scorpius, is close to the Moon on the 12th. It is close to the Moon’s lower left as they rise after midnight, and even closer at first light. As seen from Hawaii, the Moon will briefly eclipse Antares on the morning of the 13th.

 Jupiter stands a little to the lower left of the Moon at first light on the 18th. They are low in the southeast.

 The Lyrid meteor shower is at its best on the night of the 21st, especially with the Moon appearing as a thin crescent.

The Moon, Venus, and Mars congregate low in the east the morning of the 22nd. The Moon will eclipse Venus, briefly hiding the planet from view.

The Moon, the Pleiades, and the planet Mercury align low in the west-northwest as night falls on the 26th. The Pleiades star cluster is a little below the Moon, with Mercury about the same distance below the Pleiades. Mercury looks like a fairly bright star. Binoculars will enhance the view.

Venus is getting close to the Sun and is hard to spot right now. In  about a week it will become a morning object. Early risers can witness Venus in all of its glory for most of the rest of the year.

Saturn has just passed opposition but is still near its brightest for the year. Unfortunately the rings are nearly edge on right now and so are not very visible. Disappointing as that is, Saturn is still an impressive target and you should be able to pick out some of its moons even with a smaller telescope.

Mars and Jupiter are close together in the early morning sky with Jupiter being the far brighter of the two. A good

Jupiter and the Galilean Moons

telescope should pick able to image the Great Red Spot as well as at least four of the 63 known Jovian moons. The four largest moons are called the Galilean moons as they were first observed by Galileo on January 7, 1610 when he trained his home made telescope on Jupiter.