Sky Events For May 2015

Moon Phases

Full Moon

Sunday, May 3, 11:42 p.m. EDT

The Full Moon of May is known as the “Milk Moon,” “Flower Moon,”  or “Corn Planting Moon.” It rises around sunset and sets around sunrise; this is the only night in the month when the Moon is in the sky all night long. The rest of the month, the Moon spends at least some time in the daytime sky.

Last Quarter Moon

Monday, May 11, 6:36 a.m. EDT

The Last Quarter Moon rises around 2 a.m. and sets around 1 p.m. It is most easily seen just after sunrise in the southern sky.

New Moon

Sunday, May 18, 12:13 a.m. EDT

The Moon is not visible on the date of New Moon because it is too close to the Sun, but can be seen low in the East as a narrow crescent a morning or two before, just before sunrise. It is visible low in the West an evening or two after New Moon.

First Quarter Moon

Monday, May 25, 1:19 p.m. EDT

The First Quarter Moon rises around 1 p.m. and sets around 2:15 a.m. It dominates the evening sky.

Observing Highlights

Mercury at greatest elongation

Thursday, May 7, evening twilight

This is the best evening apparition of Mercury this year for observers in the northern hemisphere. Use Venus to help you locate it. Mercury is most easily located by sweeping with binoculars, but once you’ve located it, you should be able to see it with your unaided eyes

Uranus and the Moon

Friday, May 15, dawn

The Moon will pass just south of the Uranus just before sunrise.

Double shadow transit on Jupiter

Wednesday, May 20, 8:06–8:35 p.m. EDT

The shadows of Io and Ganymede will be on opposite limbs of Jupiter, while the moons Io and Callisto will be central on the disk.

Saturn at opposition

Friday, May 22, 10 p.m. EDT

Saturn will be in opposition to the Sun.

Note how most of Saturn’s moons are in the same plane as the rings, except for Iapetus, whose orbit is tilted 8.3 degrees. At opposition, Iapetus is close to maximum elongation towards the west, while Tycho is close to maximum elongation towards the east.

Double shadow transit on Jupiter

Wednesday, May 27, 10:01 p.m.–12:18 a.m. EDT

The shadow of Io chases the shadow of Ganymede across the face of Jupiter, catching up with it and passing it at 11:48 p.m. EDT. The Great Red Spot will also cross Jupiter’s disk during this period.

Planets

 Mercury is well placed for northern hemisphere observers in the evening twilight sky for the first three weeks of May.

Venus shines high in the western sky after sunset.

Mars moves from Aries to Taurus on May 3, too close to the Sun to be visible.

Jupiter is well placed in the evening sky all month.

Saturn is just north of Scorpius’ “claws.” At opposition on May 22, it is visible all night.

Uranus rises just before the Sun in Pisces.

Neptune is in the eastern morning sky in the constellation Aquarius.

If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram. 

Pluto Is A Planet, And So Is Eris

Is Pluto a planet?  What is a planet, anyhow?  We hope you’ll agree that the IAU's current answers to these questions are unclear and confusing.  Here, we propose clear and unambiguous answers to these fundamentally unclear problems.  Above all, we hope you have fun with the debate, no matter what side of it your heart may lay on.

The Planet Definition Mess

 As astronomers began to discover objects similar in size to Pluto, culminating with the discovery of Eris in 2005, it quickly became clear that if Pluto was a planet, so should Eris.  And if Eris was a planet why not some of the other newly discovered  objects. Our solar system might have dozens of planets.  One camp felt that a line needed to be drawn somewhere, and another camp felt that the newly discovered objects should be added to the list of solar system planets.

 

Illustration of the relative sizes, albedos, and colours of the largest trans-Neptunian objects.

Illustration of the relative sizes, albedos, and colours of the largest trans-Neptunian objects.

In 2006 the International Astronomical Union (IAU) met with the intention of solving the debate once and for all.  The goal was to come up with a definition for “planet”, which had never been done before.  After many days of contentious debate, the IAU passed the following resolution:

RESOLUTION 5A

The IAU therefore resolves that planets and other bodies in our Solar System, except satellites, be defined into three distinct categories in the following way:

(1) A "planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

(2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape [2], (c) has not cleared the neighbourhood around its orbit, and 

(d) is not a satellite.

(3) All other objects, except satellites, orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".

This is a poor definition that has only served to add more confusion.  With resolution 2c,  “has cleared the neighborhood around its orbit”, the IAU is trying to express that a planet should be the dominant gravitational force in its local region of the solar system.  That's not an unreasonable position.  Certainly the Earth and Jupiter are the dominant objects in their local regions.  But have any of these planets actually "cleared the neighborhood" around their orbits?  No.  Pluto is still clearly in Neptune's "neighborhood".  For that matter, Jupiter has two well-known groups of asteroids, the "Trojans", which lead and follow Jupiter along in its orbit.  For that matter, the Earth hasn't quite "cleared the neighborhood" around its orbit, either, as anyone who was near Chebalyink, Russia on Feb 15th, 2013 or Tunguska, Siberia on June 30th, 1908 can attest to.  So are Earth, Jupiter, and Neptune the dominant gravitational objects in their local neighborhoods?  Yes.  Have they "cleared their neighborhoods"?  No.

The Thousand Kilometer Rule

 Here is what the IAU should have resolved in 2006:

 (1) A "planet" [1] is a celestial body that (a) is in orbit around the Sun, (b) has a maximum surface radius greater than 1000 kilometers.

 (2) All other objects orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".

 "But that's completely unscientific" you say. "Why 1000 kilometers?  Why not 1200, or 750?"  I submit to you that the precise definition of a planet as an object at least 1000 kilometers in radius is no less "scientific" than the definition of a "kilometer" as being a unit of distance equal to 1000 meters, or a "degree" being 1/360th of a circle.

 Here is a list of the largest known objects orbiting the Sun, and their radii in kilometers:

Jupiter - 69,911
Saturn - 58,232
Uranus - 25,362
Neptune - 24,622
Earth - 6,378
Venus - 6,052
Mars - 3,390
Mercury - 2,440
Pluto - 1,184
Eris - 1,163
Makemake - 715
Haumea - 620
Quaoar - 555
Sedna - 498
Ceres - 475
Orcus - 458

By the 1000-kilometer definition, all eight classical planets would remain planets.  As would Pluto, and we add Eris.  The solar system would have exactly ten planets. Those fond of keeping Pluto's planetary status for historical reasons would retain its dignity.  And elevating Eris to a first-class planet would be an honorable nod to the cutting-edge astronomers whose work led to a need for this new definition in the first place.

And as to the "cleared the neighborhood" part of the definition?  This it the most unclear and least popular part o the IAU's 2006 definition.  It's best dealt with by being eliminated entirely.  The end game is to define the term "planet" in a manner that's simple, understandable, and satisfying.  The 1000-kilometer rule does this aptly.

If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram. 

Mercury at its Best

Now that Pluto has been demoted to a dwarf planet, Mercury is the smallest of the eight planets. With a diameter of 3032 miles (4879 km.), it is slightly more than a third of the diameter of Earth, and smaller than the solar system’s two largest moons, Ganymede and Titan. Because of its tight orbit around the sun, Mercury never strays far into the night sky, peeping tantalizingly over the horizon a few times a year. The next two weeks will be your best chance for seeing Mercury in evening twilight this year.

Timing is the secret for catching sight of Mercury. Try too early, and its tiny speck of light will be lost against the twilight sky. Try too late, and Mercury will be too close to the horizon. I’ve found the best time to be about half an hour after sunset. Binoculars are helpful in initially spotting Mercury, but once located in binoculars you should be able to see it with the unaided eye.

Currently Venus is shining brightly in the evening sky, and it can be a helpful guide to spotting Mercury, about two-thirds of the way down towards the horizon, and slightly to your right. Don’t confuse it with nearby Aldebaran, which will have a noticeably reddish color and will probably twinkle, while Mercury shines with a more steady light.

On the evening of Thursday, May 7, Mercury will be at its farthest from the Sun, making the next two weeks the best time this year for observers in the northern hemisphere to spot this elusive little planet. Credit: Starry Night software.

On the evening of Thursday, May 7, Mercury will be at its farthest from the Sun, making the next two weeks the best time this year for observers in the northern hemisphere to spot this elusive little planet. Credit: Starry Night software.

In a telescope, Mercury is a disappointing sight. Like Venus, Mercury exhibits phases as it passes between us and the sun. At present it is slightly gibbous. On Saturday, May 2, it will look just like a miniature first quarter moon. After that, it will assume a crescent shape.

Because Mercury is always seen close to the horizon, it is a challenge to see its surface markings, even in a powerful telescope. Serious observers of Mercury prefer to observe it in the daytime sky, now relatively easy to do because of computerized telescopes. But always be very careful when observing with the sun above the horizon, because even the briefest view of the sun in a telescope will do permanent harm to your eyes.

If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram. 

Starry Night 7, eclipses and ... Elmo

Like most two years olds, my daughter loves Elmo. Something about his high-pitched voice and ever-present smile I guess.

Parents innately learn to tune him out, probably to moderate the risk of going insane listening to that same shrill voice on reruns day after day.

One episode that sticks out in my mind, today more than ever perhaps, puts Elmo in a room with none other than David Beckham. The short ends after Elmo, who pesters Becks to teach him to dribble a soccer ball on his head, learns a new word... Persistence.

Persistence is an extremely important quality, and some might say a disappearing quality these days. It goes hand-in-hand with patience I think, something we can all agree is becoming scarce in this age of on-demand everything.

Persistence, as in the case of Elmo and Becks, often pays off.

Over the past few weeks, I've been involved in an exchange over the accuracy of Starry Night's eclipse predictions. One of our "power users" (who shall remain nameless for now) reported what he believed to be an issue with our calculations. They just didn't match up exactly with what NASA (and other government sites) were reporting.

The discrepancy was small; in fact, the timings were exact, to the sub-second but the sizes of the Earth's shadows (both the umbra and penumbra) were too small by a very small but noticeable fraction.

Normally no-one would even notice this, but in this case it changed our prediction for the April 4th, 2015 eclipse from a Total (as reported by NASA) to a Partial eclipse. That made all the difference to a few people.

I sit down at my 'puter. "I'll figure this out", I say to myself confidently:

  • Were we perhaps using an old or imprecise value for the Earth's diameter? Nope. That was in agreement with the USGS.
  • Were we taking the oblateness of the Earth into account? Yup. A precise calculation there too.
  • Was this somehow rounding or another error in calculation? Nope. Everything seems to check out.

After a few hours of this, I checked with my confrere, Bill (our SkySafari developer) to see if they had the same discord with NASA predictions. They did! And even better (worse, it turns out) both Starry Night, and SkySafari, two completely independently created applications, gave almost exactly the same result!

That sealed it for me. Other matters were more pressing. NASA could be wrong too (note that it's not insane to believe this, the pages we were referring to were intended for the public, maintained by a summer student and weren't necessarily vetted by anyone), or could have used slightly different values for the radius of the Earth. Were THEY accounting for the oblateness? Doubts and lack of information made it difficult.

After presenting my findings to Keiron, our head of support, I let the issue go.

Lots of other stuff to work on.

Again, the power user, and Keiron came back to me. Why were our predictions different? We claim arcsecond precision in our planet and moon positions. How could we make that claim if this discrepancy existed?

Again, I chatted with Bill. He said he had been talking with Keiron too. I Don't know what this annoying user thinks he knows that we don't. What could it be? "The Earth's atmosphere?" Says Bill. I dunno. Does NASA take it into account? It's not clear from their site. How can we compare if they don't say? The discrepancy is so small.

Lots of other stuff to work on.

Again, an email from Keiron. "Aren't you busy?" I think to myself. I open it, a curt reply, ready at my fingertips. This time, the message comes with a link.

"Do you think the Danjon rule explains the difference?" he asks:

http://www.eclipsewise.com/oh/oh-help/LEshadow.html

...

Holy s*&t!

...

Not just a clear explanation of what, how, and by how much the Earth's atmosphere contributes to the shadow, but authored by Fred Espenak himself, The Godfather of eclipse predictions! 

This page on the eclipse, with nicely outlined parameters showed something called "Shadow Enlargement":

http://www.eclipsewise.com/lunar/LEprime/2001-2100/LE2015Apr04Tprime.html

... with a link to a clear explanation of what the Danjon shadow rule is, and its value.

It turns out that the Earth's atmosphere contributes around 1/85 (just over 1%) to the diameter of the Earth's shadow... an effect that we were NOT taking into account in Starry Night or SkySafari... but are now! (SN version 7.1.2+, SkySafari ).

Starry Night has been around for almost 20 years in some form or another, and we have never taken this into account, until now.

We could all learn a little from this power user and Keiron (and Elmo for that matter). It pays to be persistent! 

Thanks for keeping at it guys. Starry Night is that much better for it.

After a few hours of this, I checked with my confrere, Bill (our SkySafari developer) to see if they had the same discord with NASA predictions. They did! And even better (worse, it turns out) both Starry Night, and SkySafari, two completely independently created applications, gave almost exactly the same result!

That sealed it for me. Other matters were more pressing. NASA could be wrong too (note that it's not insane to believe this, the pages we were referring to were intended for the public, maintained by a summer student and weren't necessarily vetted by anyone), or could have used slightly different values for the radius of the Earth. Were THEY accounting for the oblateness? Doubts and lack of information made it difficult.

After presenting my findings to Keiron, our head of support, I let the issue go.

Lots of other stuff to work on.

Again, the power user, and Keiron came back to me. Why were our predictions different? We claim arcsecond precision in our planet and moon positions. How could we make that claim if this discrepancy existed?

Again, I chatted with Bill. He said he had been talking with Keiron too. I Don't know what this annoying user thinks he knows that we don't. What could it be? "The Earth's atmosphere?" Says Bill. I dunno. Does NASA take it into account? It's not clear from their site. How can we compare if they don't say? The discrepancy is so small.

Lots of other stuff to work on.

Again, an email from Keiron. "Aren't you busy?" I think to myself. I open it, a curt reply, ready at my fingertips. This time, the message comes with a link.

"Do you think the Danjon rule explains the difference?" he asks:

http://www.eclipsewise.com/oh/oh-help/LEshadow.html

...

Holy s*&t!

...

Not just a clear explanation of what, how, and by how much the Earth's atmosphere contributes to the shadow, but authored by Fred Espenak himself, The Godfather of eclipse predictions! 

This page on the eclipse, with nicely outlined parameters showed something called "Shadow Enlargement":

http://www.eclipsewise.com/lunar/LEprime/2001-2100/LE2015Apr04Tprime.html

... with a link to a clear explanation of what the Danjon shadow rule is, and its value.

It turns out that the Earth's atmosphere contributes around 1/85 (just over 1%) to the diameter of the Earth's shadow... an effect that we were NOT taking into account in Starry Night or SkySafari... but are now! (SN version 7.1.2+, SkySafari ).

Starry Night has been around for almost 20 years in some form or another, and we have never taken this into account, until now.

We could all learn a little from this power user and Keiron (and Elmo for that matter). It pays to be persistent! 

Thanks for keeping at it guys. Starry Night is that much better for it.

Again, I chatted with Bill. He said he had been talking with Keiron too. I Don't know what this annoying user thinks he knows that we don't. What could it be? "The Earth's atmosphere?" Says Bill. I dunno. Does NASA take it into account? It's not clear from their site. How can we compare if they don't say? The discrepancy is so small.

Lots of other stuff to work on.

Again, an email from Keiron. "Aren't you busy?" I think to myself. I open it, a curt reply, ready at my fingertips. This time, the message comes with a link.

"Do you think the Danjon rule explains the difference?" he asks:

http://www.eclipsewise.com/oh/oh-help/LEshadow.html

...

Holy s*&t!

...

Not just a clear explanation of what, how, and by how much the Earth's atmosphere contributes to the shadow, but authored by Fred Espenak himself, The Godfather of eclipse predictions! 

This page on the eclipse, with nicely outlined parameters showed something called "Shadow Enlargement":

http://www.eclipsewise.com/lunar/LEprime/2001-2100/LE2015Apr04Tprime.html

... with a link to a clear explanation of what the Danjon shadow rule is, and its value.

It turns out that the Earth's atmosphere contributes around 1/85 (just over 1%) to the diameter of the Earth's shadow... an effect that we were NOT taking into account in Starry Night or SkySafari... but are now! (SN version 7.1.2+, SkySafari ).

Starry Night has been around for almost 20 years in some form or another, and we have never taken this into account, until now.

We could all learn a little from this power user and Keiron (and Elmo for that matter). It pays to be persistent! 

Thanks for keeping at it guys. Starry Night is that much better for it.

Partial solar eclipse on October 23rd

On the evening of October 23rd a partial solar eclipse takes place, ideally timed for North Americans to observe in the evening. The Moon's first contact with the Sun takes place at 4:25 PM CDT, and the moment of greatest eclipse is at 5:31 PM. These times are for an observer located in Minneapolis, MN; for other parts of the US, the times will vary slightly. Anyone wishing to view the eclipse should view it through special solar observing filters or by projecting the Sun's image. Don't ever stare directly at the Sun, even with sunglasses, and especially not through a telescope!

To simulate the partial solar eclipse in Starry Night 7 look in the Find Panel (the right sidebar) under "Today's Sky" and click on the listing for "Partial Solar Eclipse". Enjoy SN7!

Will you be viewing the partial solar eclipse today?

Double Stars around Boötes

On a May evening many years ago, I made my first exploration of the night sky. The only star pattern I could recognize was the Big Dipper, but with a star chart in a book, I used that to discover the bright star Arcturus in the constellation Boötes.

The curve of the Big Dipper's handle leads to Arcturus, the brightest star in the kite-shaped constellation of Boötes. Surrounding Boötes is an amazing variety of double stars. Credit: Starry Night software

The trick to learning the constellations is to begin with the stars you know, and use them to identify their neighbors. This same technique, known as "starhopping" is the key to discovering all the wonders hidden amongst the stars.

Start, as I did, with the Big Dipper, high overhead as the sky gets dark at this time of year. The stars that form the Dipper’s handle fall in a gentle arc, and if you project that arc away from the Dipper’s bowl, you come to a bright star. This is Arcturus, the third brightest star in the night sky, and the brightest star in the northern sky. Only Sirius and Canopus, far to the south, are brighter.

Arcturus is bright in our sky for two reasons, first because it is relatively close to us, 38 light years away, and secondly because it is inherently a bright star, much brighter than our Sun. Though larger and brighter, it is a slightly cooler star than our Sun, so appears orange to our eyes.

Although Boötes is supposed to be a ploughman in mythology, its pattern of stars most resembles a kite, with Arcturus marking the bottom of the kite where the tail attaches. Notice the little dots over the second "o" in Boötes: this indicates that the two "o"s are supposed to be pronounced separately, as "bow-oo’-tees," not "boo’-tees."

Once you have identified Boötes, you can use its stars to identify a number of constellations surrounding it. Between it and the Big Dipper are two small constellations, Canes Venatici (the hunting dogs) and Coma Berenices (Bernice's hair). To Boötes left (towards the eastern horizon) is the distinctive keystone of Hercules. Between Hercules and Boötes is Corona Borealis (the northern crown) with Serpens Caput, the head of the serpent, poking up from the south.

Although most stars appear to our unaided eyes as single points of light, anyone with access to binoculars or a telescope soon discovers that nearly half the stars in the sky are either double or multiple stars. Some of these are just accidents of perspective, one star happening to appear in the same line of sight as another, but many are true binary stars: two stars in orbit around each other, similar to the stars which shine on the fictional planet Tatooine in Star Wars.

Every star labeled on this map of Hercules, Boötes, and Ursa Major is a double star, worth exploring with a small telescope. Some, like Mizar in the Dipper’s handle, can be split with the naked eye. A closer look with a telescope shows that this is really a triple star. Others require binoculars or a small telescope. Some of the finest are Cor Caroli in Canes Venatici, Izar (Epsilon) in Boötes, Delta Serpentis, and Rho Herculis.

One of the joys of double star observing is the colour contrasts in some pairs. Others are striking for matching colours and brightness. My favorites are stars of very unequal brightness, which look almost like stars with accompanying planets.

Also marked on this chart are three of the finest deep sky objects: the globular clusters Messier 13 in Hercules and Messier 3 in Canes Venatici, and the Whirlpool Galaxy, Messier 51, tucked just under the end of the Big Dipper’s handle. You will probably need to travel to a dark sky site to spot this galaxy. A six-inch or larger telescope will begin to reveal its spiral arms, including the one that stretches out to its satellite galaxy, NGC 5195.

Starry Night 7: High Resolution Planetary Texture Collection

In recent years, NASA has conducted numerous exploratory missions that provided detailed measurements of the visual appearance and physical characteristics of most of the planets and moons in our solar system. These categories include IR/UV/visible imagery, physical, chemical and geological properties of the celestial bodies.

Measurements range from surface features to physical properties to chemical and geological characteristics. Surface features consist of topography, albedo, roughness and age. Fundamental physical properties include gravity, magnetism and temperature. Chemical and geological quantities comprise elemental composition, mineral distributions, geological maps and crustal thickness. 

Starry Night Pro Plus 7 offers a Planetary Science Texture Compilation with over 100 additional maps. Planetary images and data were derived from the latest datasets available. The original, highest quality sources were used to produce maps with maximum fidelity. Gaps and artifacts in individual datasets were corrected with data from older or alternate sources obtained by other exploratory space missions to produce consistent, high quality images that clearly illustrate the parameters of interest.
 

Earth:
Light Pollution Atlas

Jupiter:
Callisto Color
Callisto Gray
Europa Color
Europa Gray
Ganymede Color
Ganymede Gray
Io Color
Io Geology
Io Gray
Jupiter Color
Shoemaker-Levy

Mars:
Mars Albedo Color
Mars Albedo Gray
Mars Elemental Abundance Set
Mars Geoid
Mars Geological Map
Mars Gravity
Mars Magnetic Field
Mars MDIM
Mars Roughness
Mars Surface Dust Index
Mars Thermal Inertia
Mars Topo Jade
Mars Topo Spectrum
Mars Viking Color
Mars Viking MDIM Merged
Mars Viking Shaded
MOC color
MOC gray

Mercury:
Messenger Color
Messenger Gray
Mercury Messenger Color
Mercury Messenger Gray

Moon:
Clementine Color
Clementine False Color
Clementine Gray
Clementine Iron
Clementine Mineral Ratio
Clementine Optical Maturity
Lunar Gravity
Moon Crustal Thickness
Moon Elemental Abundance Set
Moon Geoid
Moon LROC Gray
Moon Roughness
Moon Temperature
Moon Topo
Moon Illusion Beetle
Moon Illusion Lady
Moon Illusion Lady Reading Book
Moon Illusion Man In Moon
Moon Illusion Rabbit
Moon Illusion St. George

Saturn:
Dione Gray
Enceladus Color
Enceladus Gray
Iapetus Color
Iapetus Gray
Mimas Gray
Phoebe Gray
Rhea Gray
Saturn Bjorn Jonsson
Saturn Hubble
Tethys Gray
Titan Color
Titan Gray
Titan IR
Titan Lakes
Titan Topo
Titan Topo scale

Sun:
Ca II 3933A
FeIX-FeX 171A
FeIX-FeX 171APNG Tiles
FeVII 195A
H-alpha
He II 304A

Venus:
Venus Geoid
Venus Gravity
Venus Magellan Color
Venus Magellan Gray
Venus Topo

Vesta:
Vesta Gray
Vesta Rock Types
Vesta Topo

Starry Night 7: Streaming Data On-Demand

Starry Night Pro Plus 6, when fully installed, occupied more than 10GBs of disk space. The sheer size of it required jumping through lots of technological hoops; from huge downloads to special DVDs, each with their own set of gotchas. This led to a lot of problems, all to deliver every last bit of data, much of which might never be accessed!

With the ever expanding volumes of interesting astronomical data available to the general public, as well as the near ubiquitous availability of high-speed internet access, Starry Night 7 was designed with a new mantra... deliver it on-demand!

Not wanting to sacrifice our tradition of beautifully simulating huge sets of astronomical data, we designed a new, robust system to stream the high-resolution, or rarely accessed data as its needed.

Not only do we now have the ability to deliver you, our users, essentially infinite amounts of astronomical data, but we can now deliver you ONLY that data which you want.

The system, at its base, is quite simple:

Zoom in on a particular piece of the sky, descend onto Mars, or choose one of dozens of available horizon panoramas and Starry Night checks your local hard disk for the necessary files. If they're found, they're loaded into the sky. If not, Starry Night makes a request to our servers to download the necessary data, streaming it to your computer where it will remain for the next time you need it.

This was done in a very limited way in Starry Night 6... only very dim USNO stars were served up by this system.

We have since expanded on that (and will continue to expand on that) to include the AllSkyImage layer and dozens of high-resolution planet surface textures. Horizon Panoramas are next to come along with individual object data, and more and deeper databases.

Some 27 GBs of data rests on our servers, waiting to be streamed! Sit back, zoom in, and enjoy!

Starry Night 7.0.2 and Beyond

Development of Starry Night 7 is proceeding quickly, so I thought I'd take a sec to update everyone on what we're working on.

In the very short term, we'll release Starry Night 7.0.2, mostly to address crashes and other incompatibilities that weren't discovered during beta-testing. We're focusing on issues that make it difficult to use the app, and features that might be broken. I'm taking this week to true up the Equipment list too.

In the weeks to come, we're going to take a solid look at all of the feature requests, suggestions and comments all of you have made, as well as usability issues discovered by our Beta-Testers.

We'll be rewriting the Observation Logging feature, with a particular emphasis on sharing logs... with each other and with other applications. We'll be sure to enable importing of your V6 logs, not to worry!

In addition to improving all of the obvious observing features, we'll be looking at other ways to share experiences with your friends and co-observers, improve add-to and refine our databases, and improve the speed of the application.

Stick with us. Lots of interesting things to come.