Scorpius Grabs the Moon!

scorpius-moon-ani   Monday September 1st the nearly first quarter Moon will be rising within the clutches of Scorpius the Scorpion as the banner graphic shows.
   When looking for or recognizing the star pattern for Scorpius most look for what could be described as the English letter J, or as I tell my younger students a ‘lazy J’.

Click on graphic to see it full size.

Click on graphic to see it full size.

   This part of the northern hemisphere late summer skies is always a treat to observe especially if the skies are dark enough to see the Milky Way. If you can find the teapot-shaped asterism for Sagittarius then look for the pour spot on the right side. Under dark skies the Milky Way looks like steam rising from the teapot. Look just off to the right, west, from the pour spout and you are looking toward the center of our galaxy, some 27,000 light years away. Here is an infrared image of the galaxy center from NASA’s 2MASS mission.

   
   
   
[centup]
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Is Earth A Dwarf Planet?

   The title is sort of misleading but after reading a press release from the NASA WISE (Wide-field Infrared Survey Explorer) mission I started thinking about the IAU official definitions for a planet that distinguishes a planet from a dwarf planet. In particular definition # 3. (see below) This thinking resulted from reading the press release which described success in determining the colors of the Trojan Asteroids that orbit at two specific points along Jupiter’s orbital path. I thought, “wait a minute”, if a planet had to have cleared its orbital path (# 3) then Jupiter with these Trojan Asteroids, and in fact Earth, Mars, and Neptune with their own Trojan Asteroids, may need to be considered as dwarf planets — by the definition.
   However the authors of the definitions took these Trojan asteroids into consideration and as the full definition explains there may be objects like the Trojan Asteroids that while orbiting the Sun along a planet’s orbital path, these objects are where they are as a result of gravitational interactions or orbital resonances with that planet, Jupiter for example. The bottom line is that there are no other objects along Jupiter’s orbital path other than those placed and held there by Jupiter’s gravitational field. And the same applies to Mars, Earth, and Neptune. Interestingly there are even moons having Trojan Satellites.
   Is Earth a Dwarf Planet? No, it is one of the 8 planets in our solar system.

   The Trojan Asteroids near Jupiter are interesting in many ways including that they are different from the asteroids we find in the main asteroid belt for example. The colors of these Jupiter Trojan asteroids are also different. Did you know that asteroids had color? Jupiter has two pair of Trojan asteroids – both at the same angle from Jupiter with one leading and the other trailing Jupiter.

  1. Orbits the Sun
  2. Has enough mass to have a spherical or round shape (at or near what is called hydrostatic equilibrium)
  3. Has cleared its neighborhood – objects along its orbital path.

Click here to go to the Qué tal in the Current Skies web site for more observing information.

I Can See Clearly Now

The next generation orbiting telescope, the James Webb Space Telescope, is not scheduled to be launched until 2018. However there is a lot of information useful for those that are simply curious, or for those teaching Earth and Space Sciences. The Webb Telescope will be used to study infrared radiation, heat energy, radiate by many objects yet invisible to our eyes without the use of optical devices like the infrared sensitive Webb Telescope.
To explain what this is all about the folks at STScI (Space Telescope Science Institute) have developed an entertaining and informative animated 8-minute video, Beyond the Visible”. The video is available for either online viewing or for download.
A related video, and one of my favorites about Infrared is Infrared: More Than Your Eyes Can See (hey Michelle!) that was produced by the Spitzer Space Telescope folks.
An offshoot of the Spitzer web site is the Cool Cosmos web site. This is the location for the video as well as many good resources for the classroom.
Here is an alternate link (on YouTube) for the video.

Click here to read the Press Release about the James Webb Space Telescope.

Hurricane Issac From Space

Hurricane Isaac: 2 Views

Here are two contrasting views of Hurricane Isaac as it approaches the Louisiana Gulf Coast, and New Orleans.
One view is of the hurricane taken by NASA’s AQUA satellite yesterday afternoon (28 August).
The second picture is a night view of the gulf coast as seen through the lens of the VIIRS (Visible Infrared Imaging Radiometer Suite) on the Suomi-NPP satellite, (Suomi National Polar-orbiting Partnership). “Suomi NPP is NASA’s next Earth-observing research satellite. It is the first of a new generation of satellites that will observe many facets of our changing Earth.”

Click here to see a night image of the hurricane taken early this morning (29 August)