Fri, 2 Nov 2007 12:12:04 -0700 (PDT)


"Glenn A. Walsh" <>  View Contact Details  View Contact Details   Add Mobile Alert


RE: Star or Planet


"Christina Grabe"


"Glenn A. Walsh" <>

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To:   Christina Grabe,

      Museum of Science and Industry, Chicago

From: Glenn A. Walsh,

      Project Director, Friends of the Zeiss


Thank you for the inquiry.


Typically, there are only two objects in the

non-daylight sky that appear like a star but are much

brighter than any of the other visible stars. These

are the planets Venus and Jupiter. And, Venus is often

much, much brighter than Jupiter.


Currently, Jupiter is only visible in the early

evening sky. In the early morning sky, Venus is quite

brilliant at this time. And, as it rises about an hour

or so before the Sun, this is what you would have seen

in the southeast just before sunrise.


Venus is shrouded in clouds, and the sunlight

reflected from these clouds makes it appear as a

bright beacon in the sky. And, if you use a telescope

or good set of binoculars, you can see Venus go

through phases similar to the Moon.


Astronomers rank celestial objects by brightness,

using "Apparent Visual Magnitude." At the present

time, the Apparent Visual Magnitude of Venus is -4.2.

In comparison, the Apparent Visual Magnitude of the

Sun: −26.73; Full Moon: −12.6; and the

brightest star in the night sky, Sirius: −1.47.

Most stars have a positive (+) Apparent Visual



Venus is so bright that it is often confused for an

airplane or an unidentified flying object,

particularly when it is near the horizon [either has

just risen or about to set]. In fact, when I was

employed with Pittsburgh's original Buhl Planetarium

and Institute of Popular Science in the 1980s and

early 1990s, during the evening hours I received many,

many "UFO" telephone calls from the public, when Venus

was visible in the sky.


So, whenever you see such a very bright object,

particularly before sunrise or after sunset [when

Venus is mostly visible], you can be pretty sure that

this is the planet Venus.




--- Christina Grabe wrote:


> Subject: Star or Planet

> Date: Fri, 2 Nov 2007 12:10:51 -0500

> From: "Christina Grabe"

> To: <>


> In the early morning sky about 6 AM, high in the

> south east sky is a

> very bright object.  Is it a star or planet and

> which every one it is,

> would you supply me with it's name?


> Thank you,


> Chris



> Museum of Science & Industry


> 57th & Lake Shore Drive


> Chicago, Ill.   60637




Glenn A. Walsh

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