Live from the Hubble Space Telescope
UPDATE # 21
PART 1: Calling all weather watchers....last chance
PART 2: Upcoming live interactions
PART 3: A night of no observing
PART 4: Challenge Questions: an answer at last
The time is NOW to register your class or homeschooler as an OFFICIAL Live From the Hubble Weather Reporter!
Next week, April 15-19, students across the nation will be reporting their daily weather observations (wind speed/direction, cloud type and cover, temperature) in a nationwide effort to provide DATA POINTS across the US (and Canada). The weather data will be incorporated into our web-based Passport to Knowledge weather maps enabling students to make comparative studies, analyses, and predictions of weather on Earth. The student's collaborative efforts parallel our Planetary Advocates analysis of weather and seasons on Neptune and Pluto.
More details can be found at our web site under Featured Activities --- Collaborative Weather Activity or here.
The webless are also invited. They can get more details by sending a mail message here.
>>>>>>>WE ESPECIALLY NEED DATA POINTS FROM THE FOLLOWING AREAS<<<<<<<<<<<
The Mountain States--Utah, Montana, Idaho, Colorado, New Mexico, Arizona, Wyoming
Mid-US: South Dakota, Illinois, Wisconsin, Northern Michigan
The South--Louisiana, Arkansas, Mississippi, Alabama, South Carolina and West Virginia
The East--Vermont, New Hampshire, Connecticut, and Massachusetts
It is not too late to register! We have 40 schools from around the United States and Canada, but we WANT YOU!! Join this opportunity to make local weather observations, collect data, and contribute your input and serve as our own special WEATHER WATCHING TEAM.
Fill out this form and mail it hereASAP.
REGISTRATION FOR PARTICIPATION --- WEATHER WATCHER ACTIVITY for week of April 15-19
Name of School:
This coming week will feature another opportunity for your students to interact with experts of the Hubble team. Please consider joining us.
On Wednesday, April 17, Alex Storrs and Tony Roman from the Space Telescope Science Institute will be available on CU-SeeMe. Their topic will be "How we prepared the HST to make your Pluto and Neptune observations". They will also be able to answer general astronomy questions.
Two separate sessions will be offered: from 9-10am Pacific (noon-1pm Eastern) and 11am-noon Pacific (2-3pm Eastern).
To participate, use the following CU-SeeMe reflector sites: 18.104.22.168 (first choice) and 22.214.171.124 (alternate if the primary experiences problems)
April 11, 1996
At one point during that last night, though, it appeared that the weather would, in fact, clear up! We sprang into action and began planning our observations for the rest of the night. This time, it was my turn to do all of the planning. I spent about an hour or more looking through our list of target stars, computing when the observations should be taken, and calculating how long the exposure times should be. But...as soon as we were ready to go, the clouds were back. Even though I only had an hour or so to do the planning, it was a good experience to get all that practice! I just wish we would have been able to observe... It was kind of sad to leave the telescope for the last time--it had become my home for 4 fabulous nights. Maybe I'll be able to go back someday. I sure hope so!
We left the mountain the next day. When I woke up, I looked out the window and said to myself, "Wow--it looks just like we're in an airplane, flying through a cloud!" And then I realized we weren't on an airplane! The clouds had become so thick and so low that, since we were still on top of the mountain, we were actually inside the cloud! It was cold and damp, and so humid that the water condensed on the branches of the trees...then, when the wind blew, it felt like it was raining!
Anyway, I spent another day at home with my parents, then came back to Baltimore. What an experience!!! Wow. I've been looking at some of our images, and they really look fantastic!
Do you remember the mysterious "wispy clouds" we found in one of the images we took? Well, I still haven't figured out what they are. My boss has been out of town, so I haven't been able to ask for his help. Hopefully, he'll be able to take a look at them next week. I promise to keep you posted about what I learn!
Well, I need to get back to work. I will write more next week!
The week before last, we asked:
We have two different answers to this question, one from Marc Buie and another from Sanjay Limaye of the University of Wisconsin - Madison:
Marc Buie writes:
There are three parts to this answer.
Sanjay Limaye from the University of Wisconsin - Madison writes:
What an excellent question! However, the answer is not easy unless you are familiar with the Pluto/Charon geometry. Let's begin at the beginning.
To describe the phase of Charon from Pluto requires a knowledge of
Remember, that "phase" describes the amount of illumination from the Sun, so we need to determine the relative positions of the Sun and Charon as seen from a point on the surface of Pluto.
Pluto's orbital is now relatively well known, although future improvements are likely since Pluto has now been observed since its discovery in 1930 for less than one third of its orbit around the sun (one Pluto year equals 248 earth years). Its orientation has been determined from the knowledge of the orbit of its moon, Charon, which has a period of 153 hours 18 minutes (6.38722 days) around Pluto. Charon is believed to be in synchronous rotation around Pluto, meaning that Pluto must also rotate about itself in the same period, 6.38722 days. Further, Charon's orbit is believed to mark the equatorial plane of Pluto, i.e. the spin axis of Pluto is parallel to that of Charon. This direction can be described by the location of Pluto's 'pole' position, or the positive spin axis (don't look up any books on astronomy, you won't find this information there!) which is at 311.63 degrees right ascension and 4.18 degrees declination (right ascension and declination are astronomical equivalents of longitude and latitude in the equatorial co-ordinate system). But exactly where is this direction? Unless you can visualize RA and Dec values into position in the sky, here is a clue. Between 1985 and 1990, we know that earth was in the plane containing the orbital plane of Charon (and hence Pluto). This how the surface of Pluto was first mapped, by observing the obscuration of Pluto by Charon every 153h1 18m apart as Charon came in front of Pluto and went behind it as it moved in its orbit. It is easy to locate earth and Pluto during that period, and that gives a good idea of the orientation of Charon's orbit around Pluto, and hence of where Pluto's spin axis is pointed at. We need to know to see how the phase of Charon would appear from Pluto.
Since the orientation of the spin axes does not change as Pluto and Charon move in their respective orbits, it is clear that at some point in future, roughly a quarter of the orbital period from about 1985, or, around 2050 (=1987+248/4), the equatorial plane would be normal (90 degrees) with the direction to the Sun. At that point, from any point on Pluto, the phase of Charon would be half moon, continuously, from either the north or the south hemispheres of Pluto, and in fact, the entire northern hemisphere of Pluto will be in continuous sunlight and the southern hemisphere will be in continuous darkness (ignoring for the moment the orbital inclination of Pluto, which is actually substantial, 17 degrees). This situation will change when Pluto changes its orbital position enough so that its spin axis is sufficiently away from the direction to the sun from Pluto, until half an orbital period later, when it will recur, except that the dark and lit hemispheres of Pluto will be switched. In between, roughly half an orbital period from 1985-1990, the earth will pass again through the Charon orbital plane, recreating the mutual eclipse events. At that time, Charon will undergo a complete change between new moon and full moon every 153 hours. Of course, Charon and solar eclipses will also occur occasionally,
At other times in its orbit, Charon will depict crescent and gibbous phases repeating every 153 hours or so, never achieving full phase or new moon.