NEW HORIZONS FLIES BY PLUTO!

On July 14, after a flight of 9 years and 3 billion miles, NASA's  NEW HORIZONS spacecraft  made its closest approach to dwarf planet Pluto, that mysterious body at the outer reaches of the Solar System.  Where NEW HORIZONS is now.

More pages on NEW HORIZONS: 
NASA's    Wikipedia's.

SKY EVENTS 2015

You might want to start with  Tonight's Sky Maps  and the USNO's  The Sky This Week.  In addition, check out today's  Sunrise, Sunset, Moonrise, Moonset!

Moon Phases:               Today's
      Calendars:    This Month's   This Year's
      List:   This Year's

MOON PHASES 2015
video credit: NASA's Scientific Visualization Studio

NOTES:

1.   New Moons essentially rise and set with the Sun and reflect no sunlight toward Earth, so they allow Deep Sky Observing all night.
2.   1st Qtr Moons generally rise near "local noon" and set near "local midnight", allowing Deep Sky Observing only during the last half of the night.
3.   Full Moons generally rise near sunset and set near sunrise, allowing no Deep Sky Observing all night.
4.   Last Qtr Moons generally rise near "local midnight" and set near "local noon", allowing Deep Sky Observing only during the first half of the night.

ECLIPSES OF 2015

2015's Eclipse "Seasons":
    late Mar thru early Apr; mid thru late Sep

THIS MONTH'S SKY MARVELS

Every month, HubbleSite and the Space Telescope Science Institute's Office of Public Outreach release an excellent video that highlights "sky happenings" for that month.  Here is the link to the site where you may view and/or download the  video for the current month.

Detailed NASA / JPL SPACE CALENDAR

This includes a lot of info on the major planets, dwarf planets, asteroids, KBO's, comets, eclipses, the Moon's occultations and more.

THE MOON

Moon's Current Distance, Apparent Size and Phase
Moon's Current Location in its Phase Cycle

View the Moon's Features  that are visible from Earth with binoculars or a low-power telescope.

To help you with you lunar observations, download these classic maps of the Moon:

USAF Lunar Earthside Hemisphere Map:
Download (hi-res JP2)    View Now (smaller version)

NASA Apollo-Era Lunar Chart:
Download (hi-res JP2)    View Now (smaller version)

Here is a great  Calendar of 2015's Moon Phases & Events  courtesy of  Newcastle Observatory.
Newcastle's Previous Moon Phase Calendars: 
2014    2013    2012    2011    2010    2009    2008   

Old Format Previous Months' Phase Calendars:
2014:  Jan      2013:  Dec    Nov    Oct    Sep    Aug    Jul    Jun    May    Apr    Mar    Feb   

CURRENT AURORA FORCASTS

      OVATION Forecast:
                  Northern Lights: Aurora Borealis
                  Southern Lights: Aurora Australis

Image credit: NOAA / NWS Space Weather Prediction Center

EARTH'S CURRENT TILT
RELATIVE TO THE SUN

Though its two principal views display Earth rotating at different speeds, this interesting Flash animation lets you  Easily Find Earth's Current Tilt Relative to the Sun.  Moreover you can change just a few Settings to view how Earth's varying tilt throughout the year causes the seasons and affects the lengths of our days and nights.  Changing the month is most instructive.  (Note: in this animation the Vernal Equinox is essentially toward the bottom of your screen in its Northern Hemisphere view and outward toward you in its Oblique view.)

EQUINOXES & SOLSTICES THROUGH MARCH 2014

WHERE IS THE SUN TODAY
ALONG THE ZODIAC?

Here's a nice interactive Flash demo showing the  Sun's Location Along the Zodiac at Various Times of Year.  Drag its red pointer right and left over the names of the months.  You can also drag the Zodiac itself.

HOW FAR NORTH OR SOUTH WILL
THE SUN RISE AND SET TODAY?

Here's a nice interactive Flash demo showing the  How Far North and South the Sun Rises and Sets at Various Times of Year.

LATEST MAJOR SOLAR ACTIVITY
VISIBLE FROM EARTH

Sunspots      Prominences, Flares, etc.

W A R N I N G !   It is never safe to look directly at the real Sun with the naked eye!  Moreover, looking at it through a telescope or binoculars without adequate safeguards—even for an instant—can cause permanent blindness!  NEVER DO IT!  To learn how to safely "observe" the real Sun, consult the professionals at your local planetarium or observatory.

GET THE LATEST AWESOME SATELLITE
VIEWS OF THE SUN WITH "HELIOVIEWER"

HelioViewer  might just be the best free solar astronomy tool on the web, giving you access to countless actual photos of the Sun from multiple satellites!  "Time-step" through photos, and save and even make movies of what you find!  This free web-tool is not to be missed.

Here's an example  movie that SkyMarvels made using HelioViewer.  It shows some incredible solar prominence activity on New Year's Eve and New Year's Day!

And to help get you started, here's the direct link to the HelioViewer User Guide.

W A R N I N G !   It is never safe to look directly at the real Sun with the naked eye!  Moreover, looking at it through a telescope or binoculars without adequate safeguards—even for an instant—can cause permanent blindness!  NEVER DO IT!  To learn how to safely "observe" the real Sun, consult the professionals at your local planetarium or observatory.

CURRENT SUN AND MAJOR PLANET
VIEWS AND CONDITIONS FROM EARTH

Distances, Apparent Sizes, Phases, Moon Locations
Sun      Mercury      Venus      Mars
Jupiter      Saturn      Uranus      Neptune

Locations Among the Constellations (w/ Geo-Coords)
Sun      Mercury      Venus      Mars
Jupiter      Saturn      Uranus      Neptune

SOLAR SYSTEM VISUALIZATIONS

Note that the next three visualizations are oriented differently from each other.  So the Vernal Equinox is in a different direction in each.

Current Locations of the Planets in their Orbits  This SkyMarvels™ visualization shows the Vernal Equinox to the right, i.e. in the 3 o'clock direction.

The Solar System in 3-D  This third-party visualization "opens" with the Vernal Equinox "obliquely upward", i.e. essentially in the 12 o'clock midnight direction.

Solar System Orrery  This third-party visualization shows the Vernal Equinox to the left, i.e. in the 9 o'clock direction.

MERCURY'S & VENUS'S SKY PATHS 2013–2014

MERCURY MESSENGER status (completed mission with impact on Mercury as expected 2015 Apr 30)

MARS'S SKY PATH 2013-2014

What's Happening On . . .

MARS TODAY
image credit: NASA Ames Research Center
Mars Global Circulation Model Group

To view the above image in a larger size, with notes on each view,  click here.

MARS CURIOSITY Location

MARS SPIRIT and OPPORTUNITY Locations

JUPITER'S SKY PATH 2013–2014

JUPITER JUNO Location

SATURN'S SKY PATH 2013–2014

SATURN CASSINI Location

CLIMATIC VS. ASTRONOMICAL SEASONS

Most school children know that the climatic seasons of the two hemispheres are the reverse of each other's.  For example, when it is Summer in the Northern Hemisphere, climatically-speaking it is Winter in the Southern Hemisphere.

Nonetheless the "astronomical" seasons, as well as their respective equinoxes and solstices, have always traditionally been named for the "climatic" seasons of the Northern Hemisphere—no doubt because roughly 90% of the human population lives north of Earth's equator!  So the Summer Solstice, for instance, is the solstice in June at the beginning of the Northern Hemisphere's summer, etc.

Unfortunately, this traditional naming convention does create a potential ambiguity.  For example, for Southern Hemisphere astronomers the "traditional" Summer Solstice occurs at the start of their climatic Winter!

This is why we often now see the less traditional (though slightly less recognizable) terms: March Equinox, June Solstice, September Equinox and December Solstice.  Because these terms are more precise, they are increasingly becoming accepted as the best ways to refer to the equinoxes and solstices.

HOW LONG IS EACH SEASON?

Since their beginnings and ends are explicitly defined by the Sun's arrival at the equinoxes and the solstices in our sky, Earth's astronomical seasons have precise durations.  Moreover, though the equinoxes and solstices are equally spaced at 90-degree intervals around the Celestial Sphere, the astronomical seasons are not of equal length!  This is because Earth's changing velocity in its elliptical orbit makes the Sun appear to arrive a little early at parts of the Celestial Sphere, and a little late at others.  The lengths of the astronomical seasons are very close to the following:

Spring: 92 3/4 days
Summer: 93 2/3 days
Autumn: 89 5/6 days
Winter: 89 days.

HALF OF EARTH IN SUNLIGHT & DARKNESS

During your voyages in CELESTIA, would you like to be able to position yourself directly over the center of the half of Earth in sunlight or the half in darkness at any time this month?  On our  Tips  page, you'll find that it's quite easy to do so!  If you're any kind of sky watcher at all, you probably know just how helpful this can be!