Venus surface images |
Venus surface images |
Mar 9 2021, 09:47 AM
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#1
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Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
I have a question arising from the recent surface images acquired by the Parker Solar Probe (but best discussed in this section, I think, if anyone has comments). Would a camera with similar specifications to WISPR but located on Earth or in Earth orbit be able in principle to image the night-side surface? It presents quite a large target when suitably placed and I imagine some sort of coronagraph arrangement could be used to exclude light from the sunlit crescent.
EDIT - link reposted here: https://www.nasa.gov/feature/goddard/2021/p...g-view-of-venus |
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Mar 17 2021, 11:35 PM
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#2
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Senior Member Group: Members Posts: 1441 Joined: 26-July 08 Member No.: 4270 |
And here's the same from Venera 14 Camera 1, taking the three usable frames for this. It looks like there was a dramatic removal of dust between two of the frames that also perturbed the... debris thing(?) near the centre of the frame. There is only one usable frame from the Venera 14 Camera 2, so I will not attempt it on the other side. It doesn't look like any dust was kicked up anyway, being the famous "smooth slab" image.
Has this been noticed before? I did some googl'ing around and found Garvin 1981 and Greeley & Arvidson (1990) which talk about dust kicked up by the landers, but I didn't read anything on visual confirmation of dust being moved by wind. -------------------- -- Hungry4info (Sirius_Alpha)
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Mar 18 2021, 01:53 AM
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#3
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Member Group: Members Posts: 611 Joined: 23-February 07 From: Occasionally in Columbia, MD Member No.: 1764 |
It looks like there was a dramatic removal of dust between two of the frames.... Has this been noticed before? I did some googl'ing .....I didn't read anything on visual confirmation of dust being moved by wind. Of course it was noticed. But it is indeed perhaps not well known, and is quite remarkable, you would typically have to wait weeks or months to see such a change on Earth As my review of Venus surface wind measurements notes "The probabilistic framework articulated in this paper supports this contention of vigorous surface transport. Surface panoramas (e.g. Garvin et al., 1984) from the Venera landers show fine material to be widely present. Of the 6 landers equipped with cameras, four returned images (the lens caps on Venera 11, 12 failed to eject). Of these, only Venera 13 and 14 provided multiple panoramas which allowed change detection. Changes in the distribution of surface particulates on the lander ring are seen in Venera 13 images (e.g. Selivanov et al., 1982; see also discussion in Ksanfomality et al., 1983). Thus, out of only two occasions in which surface particle transport could possibly have been observed, it was observed in one (with only about an hour between observations). Movement of surface particulates by wind has been observed on many occasions on Mars, indeed (e.g. Lorenz and Zimbelman, 2014), but only after years of landed spacecraft operations (e.g. Arvidson et al., 1983; Sullivan et al., 2005) and high-resolution orbital observations (e.g. Bridges et al., 2012). The paper by the original imaging investigator is Selivanov, A.S. et al., 1982. Evolution of the Venera 13 imagery. Sov. Astron. Lett. 8, 433–436. |
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