{"id":835,"date":"2025-01-09T23:21:01","date_gmt":"2025-01-09T23:21:01","guid":{"rendered":"https:\/\/david.bookstaber.com\/?p=835"},"modified":"2025-01-09T23:21:05","modified_gmt":"2025-01-09T23:21:05","slug":"bright-planets-venus-and-mars","status":"publish","type":"post","link":"https:\/\/david.bookstaber.com\/?p=835","title":{"rendered":"Bright Planets: Venus and Mars"},"content":{"rendered":"\n

Coming into 2025, have you noticed that Venus and Mars are growing quite bright? Looking at a map of planetary positions<\/a> it’s easy to see why Mars is approaching a point of peak apparent brightness (which it will reach on January 16): it’s on the same side of the sun as we are, so it’s relatively close; and we are aligned to see the full reflection of the sun-lit “day” side.<\/p>\n\n\n

\n
\"\"
Inner planet positions on 16 January 2025<\/figcaption><\/figure>\n<\/div>\n\n\n

With Venus it’s not as easy to figure out when its apparent brightness will be maximized. When Venus is closest to Earth we are looking at its night side, so there’s no reflected light to see. When we can see the full day side of Venus it’s at its furthest from Earth on the other side of the sun, so it’s reflecting the maximum amount of light in our direction, but being so much further away the amount of light that reaches us is lower. In fact Venus goes through “phases” just like our moon does based on its position relative to the Earth and Sun, as shown in this diagram:<\/p>\n\n\n

\n
\"\"
Phases of Venus: How much of the “day” side of Venus we can see at different points in its orbit relative to Earth.<\/figcaption><\/figure>\n<\/div>\n\n\n

Next is another diagram that shows two significant points<\/a> in the relative orbit of Venus: “Greatest Elongation<\/a>” is when (from our perspective) the angular distance between Venus and the sun is largest. It turns out that the peak apparent brightness for Venus occurs when it is just inside its points of greatest elongation, with slightly less than half of its day side facing Earth. <\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Venus is at greatest eastern elongation<\/a> on January 10, which puts it at its highest point in the evening sky. Its brightness will peak on February 14<\/a>, at which point it will be more than 20 times brighter than the brightest star we can see (Sirius). This is so bright that it can be seen during broad daylight, if you know where to look.<\/p>\n","protected":false},"excerpt":{"rendered":"

Coming into 2025, have you noticed that Venus and Mars are growing quite bright? Looking at a map of planetary…<\/p>\n","protected":false},"author":1,"featured_media":844,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[11],"tags":[],"class_list":["post-835","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-skies","post-archive"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/david.bookstaber.com\/WP\/wp-content\/uploads\/2025\/01\/Planets20250116.jpg","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/david.bookstaber.com\/index.php?rest_route=\/wp\/v2\/posts\/835","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/david.bookstaber.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/david.bookstaber.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/david.bookstaber.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/david.bookstaber.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=835"}],"version-history":[{"count":3,"href":"https:\/\/david.bookstaber.com\/index.php?rest_route=\/wp\/v2\/posts\/835\/revisions"}],"predecessor-version":[{"id":854,"href":"https:\/\/david.bookstaber.com\/index.php?rest_route=\/wp\/v2\/posts\/835\/revisions\/854"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/david.bookstaber.com\/index.php?rest_route=\/wp\/v2\/media\/844"}],"wp:attachment":[{"href":"https:\/\/david.bookstaber.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=835"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/david.bookstaber.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=835"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/david.bookstaber.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=835"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}