Scripts to get the NASA Image Of the Day (iotd) and NASA Astronomy Picture of the Day (apod)

apod.ps1

# Download and open the NASA Astronomy picture of the day (apod)
# Download to target folder $TargetFolder (relative to this script's location)
# https://apod.nasa.gov/apod/archivepix.html

param
(
	[string]$TargetFolder = "images"
)

$ErrorActionPreference = "Stop"
. "$PSScriptRoot/util.ps1"

$api_key = Get-Content("$PSScriptRoot/ApiKey.txt")
$date = Get-Date -format "yyyy-MM-dd"
$RootUrl = "https://api.nasa.gov/planetary/apod"
$PageUrl = "${RootUrl}?api_key=${api_key}&date=${date}"
Write-Output "PageUrl = $PageUrl"

$hdurl = GetHdUrl($PageUrl)
Write-Output "ImageUrl = $hdurl"

DownloadImage $hdurl "images/apod"

exit

iotd.ps1

# Download and open the NASA Image of the day (iotd)
# Download to a path $TargetFolder (relative to this script's location)
# https://www.nasa.gov/multimedia/imagegallery/iotd.html

param
(
	[string]$TargetFolder = "images/iotd"
)

$ErrorActionPreference = "Stop"

# Get the most recent item from NASA's RSS feed
$rssFeed = [xml](Invoke-WebRequest "https://www.nasa.gov/rss/dyn/lg_image_of_the_day.rss")
$PageUrl = $rssFeed.rss.channel.item[0].link
echo "PageUrl = $PageUrl"
$mostRecentItem = (Invoke-WebRequest $PageUrl) 

# Find the image in the page
$ImageOfTheDay = $mostRecentItem.AllElements | Where-Object {$_.tagName -eq "meta" -and $_.property -eq "og:image"}
$ImageUrl = $ImageOfTheDay.content
echo "ImageUrl = $ImageUrl"

# Set the absolute target file path
$FileName = $ImageUrl.SubString($ImageUrl.LastIndexOf('/') + 1)
$AbsolutePath = Join-Path $PSScriptRoot ($TargetFolder)
$TargetFilePath = Join-Path $AbsolutePath ($FileName)

if (!(test-path($TargetFilePath)))
{
	# Download
	echo "Downloading $TargetFilePath"
	mkdir $AbsolutePath -Force | Out-Null
	Invoke-WebRequest $ImageUrl -OutFile $TargetFilePath

	# Open locally with the default app
	start $TargetFilePath
} else {
	echo "Target file already exists"
}

exit

util.ps1

function GetHDUrl ($PageUrl)
{
	$response = Invoke-WebRequest -URI $PageUrl
	if ($response.StatusCode -eq 200)
	{
		$responseContent = $response.Content
		$hdurlMatch = ($responseContent.split(",") | select-string("hdurl"))
		if ($hdurlMatch)
		{
			$hdurl = $hdurlMatch.Line -replace '"hdurl":"', '' -replace '"', ''
			return $hdurl
		} else {
			# sometimes the picture of the day is a video
			Throw "hdurl not found sry"
		}
	}
	else
	{
		Throw "invalid response code"
	}
}

function DownloadImage ($ImageUrl, $TargetFolder)
{
	# Set the absolute target file path
	$AbsolutePath = Join-Path $PSScriptRoot $TargetFolder
	
	$startPosition = $ImageUrl.LastIndexOf('/')
	$FileName = $ImageUrl.SubString($ImageUrl.LastIndexOf('/') + 1)
	$TargetFilePath = Join-Path $AbsolutePath $FileName

	if (!(test-path($TargetFilePath)))
	{
		# Download
		mkdir $AbsolutePath -Force | Out-Null
		Invoke-WebRequest -Uri $ImageUrl -OutFile $TargetFilePath

		# Open locally with the default app
		Start-Process $TargetFilePath
	} else {
		Write-Output "Target file already exists"
	}
}

moved to a normal repo: https://github.com/mrreband/nasa-images