Category: Sky Events

Sky events

Mars and Jupiter

Over the next few mornings Mars and Jupiter will rendezvous in the dawn sky. This morning sees the two a little over 2° apart. Over the next few days that will narrow quickly with close approach occurring on the mornings of July 21st and 22nd with about 50′ of separation between the two planets. By the 26th the distance between the pair will again have grown to over 2°.

Throughout the encounter the two planets will precede the Sun by about 25°, rising about 04:00HST, well placed for observation.

Keep an eye out for Mercury below the pairing, a 2nd magnitude object about halfway between the conjunction and the rising Sun. The innermost planet will reach maximum elongation on July 29th.

The mornings of August 3rd and 4th will see a thin crescent Moon slide along the line of three planets in the dawn.

Apehelion

Today the Earth is furthest from the Sun, a point called apehelion. We will be about 152,096,000km (94,508,000miles) from the Sun. Compare this to the 147,099,000km (91,403,000miles) we were be at perihelion on January 1st, a difference of about 4,996,000km (3,104,000miles) occurring throughout one orbit.

It may seem odd that we are actually at the furthest for the middle of northern summer, you just have to remember that proximity to the Sun is not the cause of the seasons. The seasons are caused by the axial tilt of the Earth, creating short and long days throughout the year, with a resulting change in the angle and intensity of the sunlight.

2013 Solstices and Equinoxes
  UT HST
Perihelion Jan 2 00:59UT Jan 1 14:59HST
Spring Equinox Mar 20 11:02UT Mar 20 01:02HST
Summer Solstice Jun 21 05:04UT Jun 20 19:04HST
Apehelion Jul 5 18:59UT Jul 5 08:59HST
Fall Equinox Sep 22 20:44UT Sep 22 10:44HST
Winter Solstice Dec 21 17:11UT Dec 21 07:11HST
 
Source: NASA Sky Calendar

 

The Moon, Mars and Jupiter

Tomorow morning, July 6th, will see a nice 5-7° triangle made up of a slim crescent Moon, Mars and Jupiter. Look for the trio to start rising about 04:30 HST with Mars rising first, followed by a 2.5% illuminated Moon. Last up will be Jupiter, rising about 04:55 HST. The Sun will not rise until 05:48 giving plenty of time to enjoy this conjunction.

Jupiter Appears in the Dawn

This week will see the reappearance of Jupiter in the dawn sky. This morning the planet will be 10° above the rising Sun, climbing quickly higher each morning. Look for a bright, -2 magnitude object directly above the bright glow of dawn.

Over the next couple weeks there will be a nice series of conjunctions between Jupiter, Mars, Mercury and the Moon.

Full Moon

Full Moon
Full Moon taken 27Aug2007, 90mm f/12 APO and Canon 20Da
Full Moon will occur today at 01:32HST.

This full Moon will be a perigee full Moon, with the Moon appearing a bit larger and brighter. Today lunar perigee occurs within minutes of full, producing a full moon that is about 12% larger and 30% brighter than if full occurs while the Moon is at apogee.

Continue reading “Full Moon”

The Portents of ISON

Comets have long been regarded as omens of extraordinary portent. Novae, eclipses, conjunctions, anything seen in the sky can serve in this role, but bright comets have always held a special awe.

C/2007N3 Lulin
Comet C/2007 N3 Lulin on the morning of 22 Feb 2009
Even today those who seek signs are quick to seize upon any unusual astronomical event. A few months ago it was meteors, events over Chelyabinsk grabbing the attention. With ISON entering the inner solar system the attention shifts.

Bright comets are invariably seen as omens by some. History is littered with stories of comets and prophesies. This has not changed, there are many recent examples… Hale-Bopp, Hyakutake, Elenin, each has been used to make all manner of wild predictions. Comet C/2012 S1 ISON certainly fits the role. It will most likely be quite bright, easily visible without optical aid. It may even be visible in the daytime.

Continue reading “The Portents of ISON”

Summer Solstice

Summer solstice occurs today at 19:04HST. Today the Sun will occupy the most northerly position in the sky of the year. The term solstice comes from the latin terms Sol (the Sun) and sistere (to stand still). On this day the Sun seems to stand still as it stops moving northwards each day and begins move to the south. This is the first day of summer as marked by many cultures in the northern hemisphere. Alternately this is the first day of winter for those living south of the equator.

Many calendars will mark Jun 21 as the beginning of summer this year, this is correct for much of the world. Here in Hawaii the solstice will occur on the 20th when correcting for the time zone difference.

2013 Solstices and Equinoxes
  UT HST
Perihelion Jan 2 00:59UT Jan 1 14:59HST
Spring Equinox Mar 20 11:02UT Mar 20 01:02HST
Summer Solstice Jun 21 05:04UT Jun 20 19:04HST
Apehelion Jul 5 18:59UT Jul 5 08:59HST
Fall Equinox Sep 22 20:44UT Sep 22 10:44HST
Winter Solstice Dec 21 17:11UT Dec 21 07:11HST
 
Source: NASA Sky Calendar