Sky, seasons and weather¶
The clock¶
The sky follows a clock with five modes. Tap the clock in the top bar (on a phone, Time of day in the three-dot menu) to step through them.
| Mode | The sky |
|---|---|
| Live | Your own time. The sun is where it is now for your place, the moon shows its current phase, and the clock names the next sunrise or sunset. |
| Dawn, Day, Dusk, Night | Held at that hour. |
At night the stars come out, the lantern lights the road, and lamps light the redwood and the exhibits from their feet. Each visit starts on Live; a mode you pick lasts until you reload.
Where the sky is placed¶
The sun, moon and stars are placed for where you are. The browser asks for your location once; if you allow it, the forest uses it, rounded to 0.1 degree and kept only in this browser. If you refuse, the forest estimates a place from your time zone. Either way the sky is right for your hemisphere and season.
The privacy page covers what the forest keeps.
The stars¶
The night sky is the real one: the 5,080 stars of magnitude 6 or brighter from the Yale Bright Star Catalogue, placed for the clock's time and your place. Size follows brightness and color follows the star's own, and stars fade toward the horizon. Look up with Up, or drag the view up, at night to see them. Twilight washes out the faint stars first, so at dusk only the brightest are out, and the moon hides the stars behind its disc.
The planets¶
Mercury, Venus, Mars, Jupiter and Saturn stand where they are tonight among the stars, as steady points a little larger than the brightest stars and tinted their own colors: Mars orange, Saturn pale gold. Their positions come from JPL's approximate Keplerian elements (Standish), good to about an arcminute, and their brightness from Mallama and Hilton (2018). Like the stars, they fade in twilight, fog and cloud, and hide behind the moon.
Tonight's sky¶
About (?, the info button in the top bar, or on a phone the three-dot menu) has a Tonight's sky section for the real date, whatever the clock is set to: the moon's phase and the next full and new moon, the meteor showers active now and coming up, which planets are up tonight with when they rise or set and where they stand highest, and where to find Polaris. North is the top of the minimap and the red point of the compass rose around the redwood. Use my location there places the sky for where you are, if you did not allow it when play started.
Meteors¶
Meteors cross the night sky at the rates a dark sky would show tonight. A few an hour are sporadic, from no shower. During a shower the rate climbs, and its meteors run outward from the shower's radiant, the point among the stars that the shower is named for. The radiant must be above the horizon for its shower to show, and the higher it stands the more meteors there are.
Fast meteors are brief and white with a green cast; slow ones last longer and burn yellow. Like the stars, meteors are lost in twilight, fog and cloud.
| Shower | Peak | Rate at peak (per hour) |
|---|---|---|
| Quadrantids | 3 to 4 January | 110 |
| Lyrids | 22 April | 18 |
| Eta Aquariids | 6 May | 50 |
| Southern Delta Aquariids | 30 July | 25 |
| Perseids | 12 to 13 August | 100 |
| Draconids | 8 October | 10 |
| Orionids | 21 October | 20 |
| Leonids | 17 November | 15 |
| Geminids | 14 December | 150 |
| Ursids | 22 December | 10 |
The rates are zenithal hourly rates: a dark sky with the radiant overhead. A real night shows fewer, and so does the forest. Even at the Perseids' peak, expect a meteor every minute or two across the whole sky.
To see a shower at its peak, add ?meteors= to the address with the
shower's name in lowercase, hyphenated (perseids, eta-aquariids,
delta-aquariids). Add : and a number to multiply its rate. A number
alone, such as ?meteors=10, multiplies tonight's whole sky: the sporadic
meteors and every shower in season. Set the clock to Night first. For
example:
https://flux-frontiers.github.io/knowledge_press/?meteors=geminids:20
Seasons¶
Each visit starts in the season of the date where you are: astronomical seasons, from the equinoxes and solstices, and half a year on south of the equator. Pick another under Environment in settings.
| Season | The forest |
|---|---|
| Spring | Fresh leaves, the canopy filling in |
| Summer | Full canopy |
| Autumn | Turned leaves, the canopy thinning |
| Winter | No leaves. The wood is the point: every limb and its thickness |
A season you pick lasts until you reload.
Fog and weather¶
Fog in settings sets how thick the standing haze is, from clear to heavy.
Random weather, off by default, adds the day's own weather: morning fog that builds and burns off, from mist to pea soup, and cloud that grays the sky and dims the sun and the stars. The weather is rolled every 12 minutes and is likeliest at dawn. Turn it on under Environment in settings; the setting shows what the weather is now.
To pin the weather for a screenshot, add ?weather= to the address, with
one of clear, clouds, mist, fog or soup. For example:
https://flux-frontiers.github.io/knowledge_press/?weather=soup